Steps to Reproduce:
1. install foreman 2.3 / katello 3.18 with pulp2
2. create yum repository with ignorable content = drpm
3. upgrade to foreman 2.5 / katello 4.1 with migration to pulp3
4. try to modify the product / repository

Result:
The modification fails with error:
An error occurred saving the Product: Invalid value specified for ignorable content. Permissible values srpm

It appears that drpm is no longer a vailid value for ignorable content (#32658), but the value is not removed during migration

<pre><code class="text">
# hammer repository info --product-id 208 --name "SLES Client 12SP5 ARM" --organization Test
Id:                      1891
Name:                    SLES Client 12SP5 ARM
Label:                   SLES_Client_12SP5_ARM
Description:             
Organisation:            Test
Red Hat Repository:      no
Content Type:            yum
Mirror on Sync:          yes
Url:                     […]
Publish Via HTTP:        yes
Published At:            https://or.supp205.mk/pulp/content/639827e8-06a2-4445-b3cc-293403d48e79/Library/custom/SLES_Client_ARM/SLES_Client_12SP5_ARM/
Relative Path:           639827e8-06a2-4445-b3cc-293403d48e79/Library/custom/SLES_Client_ARM/SLES_Client_12SP5_ARM
Download Policy:         immediate
Ignorable Content Units: drpm, srpm
HTTP Proxy:              
    Id:                1
    Name:              default
    HTTP Proxy Policy: global_default_http_proxy
Product:                 
    Id:   208
    Name: SLES Client ARM64
GPG Key:                 Sync:                    
    Status:         Success
    Last Sync Date: about 1 hour
Created:                 2021/10/18 09:35:17
Updated:                 2021/11/22 11:15:59
Content Counts:          
    Packages:       9
    Source RPMS:    0
    Package Groups: 0
    Errata:         0
    Module Streams: 0

</code></pre>