Add support for ubuntu-oracular

[aljazerzen]

• add to Makefile SUPPORTED_TARGETS
• run make
• generate gh actions

[aljazerzen]

When I ran make in integration/linux/ in a clean repo, a snippet was removed from all Dockerfiles.

1ec89b7

@elprans Can you confirm that this is ok?

[elprans]

The patch is fine, but I have a question of whether we really want to start building native packages for non-LTS Ubuntu releases. Every target adds to release time (and costs $$ in runner time). What was the original impetus here? If someone is trying to install on a non-LTS release of Ubuntu then the most recent preceding LTS repo should work (i.e use noble instead of oracular).

[aljazerzen]

This is the original issue: geldata/gel#8544

I don't know if a package for noble LTS could be installed on oracular.

[aljazerzen]

So we are fine with merging this @elprans? But not adding targets in the main repo.

I'll need these dockerfiles for the "test install from LTS build".