Description of problem:

Generating an incremental export with syncable format, generates an export with a missing file on the repodata directory.

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

How reproducible:
Always

Steps to Reproduce:
1. Create a CV with a repository that contains a productid (example repo: Red Hat Ansible Engine 2 for RHEL 8 x86_64 RPMs )
2. Do a complete export of the CV:

hammer content-export complete version --id 41 --format syncable

3. Create a new version of the CV
4. Export CV again, this time an incremental:

~~~
hammer content-export incremental version --id 42 --format syncable
~~~

Note the files on the repodata directory:

~~~

1. ls |sort
   2ad01aecc583cdede5a1489ee50efd97c48b923b586d24fb83b42f5c9103b85b-other.xml.gz
   5ac9d773403beea431e1d08255b782b8bb38e61cd458254bb0cbde907f444a77-updateinfo.xml.gz
   641203f1aa0962bbb1af40e20142c824e669323aaee862acd3eea80e046ccc92-primary.xml.gz
   67120121d59a4351342ec001ccc4e7ad4520175029770bbda447c0186ed9f1e9-filelists.sqlite.bz2
   8e91c89c9670575d4123bc37cd0cfb9e1f7a57a9b9b93c2491a67678fa7ec9d4-filelists.xml.gz
   a27718cc28ec6d71432e0ef3e6da544b7f9d93f6bb7d0a55aacd592d03144b70-comps.xml
   ee7bbcac9b13fa0a8fe3aa083e4200c5391c945b76feb59e887c4d2e36944371-other.sqlite.bz2
   f8d2107d953c43ede24bf85033c8ca025f1b32194e99b3919231ab0ce35c217a-primary.sqlite.bz2
   repomd.xml
   ~~~

Looking inside repomd.xml, there will be a reference to file of data type "productid" which is missing:

~~~

1. grep productid repomd.xml -A2
   <data type="productid">
   <checksum type="sha256">55a5ce52b4fe56961ccab8f58d2ac36230d09491d627e09f685d4b2ddd50e55b</checksum>
   <location href="repodata/7034ae03-a219-4911-9337-2118fa5768e8"/>
   ~~~

Actual results:
productid file is missing from repodata

Expected results:
A complete export of the repodata. An incremental export should only affect artifacts and not metadata.

Additional info: