Remove the pattern in the server container image

[cbosdo]

What does this PR change?

The pattern is yet another level to aggregate packages and is no longer required with containers. Move them all into the Dockerfile.

Some packages for SUSE Manager only or architecture specific will need to come from the OBS project configuration EXTRAPACKAGES though.

GUI diff

No difference.

• DONE

Documentation

• No documentation needed: only internal and user invisible changes

• DONE

Test coverage

• No tests: dockerfile is not really tested

• DONE

Links

Issue(s): #
Port(s): # add downstream PR(s), if any

• DONE

Changelogs

Make sure the changelogs entries you are adding are compliant with https://github.com/uyuni-project/uyuni/wiki/Contributing#changelogs and https://github.com/uyuni-project/uyuni/wiki/Contributing#uyuni-projectuyuni-repository

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Re-run a test

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• Re-run test "changelog_test"
• Re-run test "backend_unittests_pgsql"
• Re-run test "java_pgsql_tests"
• Re-run test "schema_migration_test_pgsql"
• Re-run test "susemanager_unittests"
• Re-run test "javascript_lint"
• Re-run test "spacecmd_unittests"

Before you merge

Check How to branch and merge properly!

[cbosdo]

Note that the OBS project configs will adjustments:

• PRODUCT_PATTERN_PREFIX can be dropped
• susemanager-branding-oss needs to be added to EXTRAPACKAGES variable for SUSE Manager
• syslinux-x86_64 needs to be added to EXTRAPACKAGES variable for non x86_64 and syslinux for x86_64.

[cbosdo]

Here is the prjconf setting up the EXTRAPACKAGES for Uyuni:

%ifarch x86_64
BuildFlags: dockerarg:EXTRAPACKAGES=shim%20syslinux
%else
%ifarch aarch64
BuildFlags: dockerarg:EXTRAPACKAGES=shim%20syslinux-x86_64
%else
BuildFlags: dockerarg:EXTRAPACKAGES=syslinux-x86_64
%endif
%endif

[cbosdo]

OBS fails to understand the list of packages from the EXTRAPACKAGES value and only downloads the first one. The image build then breaks because the other packages are not available.
In order to work around this I tried building the image with Kiwi, but this requires tito to be patched: https://build.opensuse.org/requests/1231896. Note that I haven't tested the tito tagging with that SR yet.

[cbosdo]

The original issue I wanted to fix with this PR can be solved with https://build.opensuse.org/requests/1231890. I'm not sure we need this one in the end.