Upstream let me know that at least https://hg.prosody.im/trunk/rev/558f0555ba02 is needed additionally.

Same here after update.

# systemctl status prosody.service 
● prosody.service - Prosody XMPP (Jabber) server
     Loaded: loaded (/usr/lib/systemd/system/prosody.service; enabled; vendor preset: disabled)
     Active: failed (Result: exit-code) since Thu 2021-02-25 17:32:48 CET; 11s ago
   Main PID: 12903 (code=exited, status=1/FAILURE)
        CPU: 10ms

févr. 25 17:32:48 Icaricio systemd[1]: prosody.service: Scheduled restart job, restart counter is at 8.
févr. 25 17:32:48 Icaricio systemd[1]: Stopped Prosody XMPP (Jabber) server.
févr. 25 17:32:48 Icaricio systemd[1]: prosody.service: Start request repeated too quickly.
févr. 25 17:32:48 Icaricio systemd[1]: prosody.service: Failed with result 'exit-code'.
févr. 25 17:32:48 Icaricio systemd[1]: Failed to start Prosody XMPP (Jabber) server.


# prosodyctl 
general             warn	Support for Lua 5.4 is experimental, please report any issues
/usr/bin/lua: /usr/lib64/prosody/util/async.lua:164: bad argument #1 to 'close' (thread expected, got boolean)
stack traceback:
	[C]: in function 'coroutine.close'
	/usr/lib64/prosody/util/async.lua:164: in method 'run'
	/usr/bin/prosodyctl:1411: in main chunk
	[C]: in ?


# cat /var/log/prosody/prosody.err
Feb 25 13:11:06 modulemanager	error	Error initializing module 'websocket' on '<name.tld>': /usr/lib64/prosody/net/websocket/frames.lua:12: No bit module found. See https://prosody.im/doc/depends#bitop
stack traceback:
	[C]: in function 'assert'
	/usr/lib64/prosody/net/websocket/frames.lua:12: in main chunk
	[C]: in upvalue '_real_require'
	/usr/lib64/prosody/util/startup.lua:201: in function 'require'
	/usr/lib64/prosody/modules/mod_websocket.lua:23: in main chunk
	[C]: in function 'xpcall'
	/usr/lib64/prosody/core/modulemanager.lua:183: in upvalue 'do_load_module'
	/usr/lib64/prosody/core/modulemanager.lua:261: in function 'core.modulemanager.load'
	/usr/lib64/prosody/core/moduleapi.lua:158: in function 'core.moduleapi.depends'
	/usr/lib64/prosody/prosody-modules-enabled/mod_conversejs/mod_conversejs.lua:15: in function </usr/lib64/prosody/prosody-modules-enabled/mod_conversejs/mod_conversejs.lua:14>
	...	(skipping 2 levels)
	/usr/lib64/prosody/core/modulemanager.lua:183: in upvalue 'do_load_module'
	/usr/lib64/prosody/core/modulemanager.lua:261: in function 'core.modulemanager.load'
	/usr/lib64/prosody/core/modulemanager.lua:83: in function 'core.modulemanager.load_modules_for_host'
	/usr/lib64/prosody/util/events.lua:79: in function </usr/lib64/prosody/util/events.lua:75>
	(...tail calls...)
	/usr/lib64/prosody/core/hostmanager.lua:108: in function 'core.hostmanager.activate'
	/usr/lib64/prosody/core/hostmanager.lua:58: in field '?'
	/usr/lib64/prosody/util/events.lua:79: in function </usr/lib64/prosody/util/events.lua:75>
	(...tail calls...)
	/usr/lib64/prosody/util/startup.lua:393: in function 'util.startup.prepare_to_start'
	/usr/lib64/prosody/util/startup.lua:629: in function 'util.startup.prosody'
	/usr/lib64/prosody/util/async.lua:139: in upvalue 'func'
	/usr/lib64/prosody/util/async.lua:127: in function </usr/lib64/prosody/util/async.lua:125>


After downgrading to prosody-0.11.7-1.fc33.x86_64, I found an other alert about websocket support with lua-bitop but Prosody works fine:
# systemctl status prosody.service 
● prosody.service - Prosody XMPP (Jabber) server
     Loaded: loaded (/usr/lib/systemd/system/prosody.service; enabled; vendor preset: disabled)
     Active: active (running) since Thu 2021-02-25 17:35:00 CET; 1s ago
   Main PID: 13776 (prosody)
      Tasks: 1 (limit: 18845)
     Memory: 12.7M
        CPU: 620ms
     CGroup: /system.slice/prosody.service
             └─13776 /usr/bin/lua /usr/bin/prosody -F

févr. 25 17:35:00 Icaricio systemd[1]: Started Prosody XMPP (Jabber) server.
févr. 25 17:35:00 Icaricio prosody[13776]: **************************
févr. 25 17:35:00 Icaricio prosody[13776]: Prosody was unable to find lua-bitops
févr. 25 17:35:00 Icaricio prosody[13776]: This package can be obtained in the following ways:
févr. 25 17:35:00 Icaricio prosody[13776]:         Source:           http://bitop.luajit.org/
févr. 25 17:35:00 Icaricio prosody[13776]:         luarocks:         luarocks install luabitop
févr. 25 17:35:00 Icaricio prosody[13776]:         Debian/Ubuntu:    sudo apt-get install lua-bitop
févr. 25 17:35:00 Icaricio prosody[13776]: WebSocket support will not be available
févr. 25 17:35:00 Icaricio prosody[13776]: More help can be found on our website, at https://prosody.im/doc/depends
févr. 25 17:35:00 Icaricio prosody[13776]: **************************

FEDORA-2021-160a578c2e has been submitted as an update to Fedora 33. https://bodhi.fedoraproject.org/updates/FEDORA-2021-160a578c2e

FEDORA-2021-72d5a62023 has been submitted as an update to Fedora 34. https://bodhi.fedoraproject.org/updates/FEDORA-2021-72d5a62023

FEDORA-2021-72d5a62023 has been pushed to the Fedora 34 testing repository.
Soon you'll be able to install the update with the following command:
`sudo dnf upgrade --enablerepo=updates-testing --advisory=FEDORA-2021-72d5a62023`
You can provide feedback for this update here: https://bodhi.fedoraproject.org/updates/FEDORA-2021-72d5a62023

See also https://fedoraproject.org/wiki/QA:Updates_Testing for more information on how to test updates.

FEDORA-2021-160a578c2e has been pushed to the Fedora 33 testing repository.
Soon you'll be able to install the update with the following command:
`sudo dnf upgrade --enablerepo=updates-testing --advisory=FEDORA-2021-160a578c2e`
You can provide feedback for this update here: https://bodhi.fedoraproject.org/updates/FEDORA-2021-160a578c2e

See also https://fedoraproject.org/wiki/QA:Updates_Testing for more information on how to test updates.

Works fine. Fix the bug.

FEDORA-2021-160a578c2e has been pushed to the Fedora 33 stable repository.
If problem still persists, please make note of it in this bug report.

FEDORA-2021-72d5a62023 has been pushed to the Fedora 34 stable repository.
If problem still persists, please make note of it in this bug report.

FEDORA-2021-72d5a62023 has been pushed to the Fedora 34 stable repository.
If problem still persists, please make note of it in this bug report.