Description of problem:

When updating the microcode_ctl package, dangling symlinks remain installed in the kernel-specific /lib/firmware/<kernel> directory:
-------- 8< ---------------- 8< ---------------- 8< ---------------- 8< --------
# find /usr/lib/firmware -xtype l
/usr/lib/firmware/4.18.0-348.20.1.el8_5.x86_64/intel-ucode/06-86-04
/usr/lib/firmware/4.18.0-348.20.1.el8_5.x86_64/intel-ucode/06-86-05
/usr/lib/firmware/4.18.0-372.9.1.el8.x86_64/intel-ucode/06-86-04
/usr/lib/firmware/4.18.0-372.9.1.el8.x86_64/intel-ucode/06-86-05
/usr/lib/firmware/4.18.0-372.26.1.el8_6.x86_64/intel-ucode/06-86-04
/usr/lib/firmware/4.18.0-372.26.1.el8_6.x86_64/intel-ucode/06-86-05
-------- 8< ---------------- 8< ---------------- 8< ---------------- 8< --------

This happens when microcodes stop being shipped, e.g. "intel-ucode/06-86-04" when updating from **microcode_ctl-4:20210608-1.el8** to latest (**microcode_ctl-4:20220207-1.20220510.1.el8_6**).

Version-Release number of selected component (if applicable):

microcode_ctl-4:20220207-1.20220510.1.el8_6 and later

How reproducible:

Always

Steps to Reproduce:
1. Install microcode_ctl-4:20210608-1.el8
2. Update to microcode_ctl-4:20220207-1.20220510.1.el8_6

or

1. Install latest microcode_ctl-4:20220207-1.20220510.1.el8_6
2. Downgrade to microcode_ctl-4:20210608-1.el8

Actual results:

Microcodes that are not shipped anymore remain dangling for all installed kernels

Expected results:

No dangling symlinks

Additional info:

The root cause is no cleaning of unshipped files in /usr/libexec/microcode_ctl/update_ucode, only cleaning of ucode_with_caveats microcodes