ci: use branches inclusion instead of branches-ignore exclusion

[blackboxsw]

We have seen our branches-ignore still trigger gh-cla, alternate distro and integration tests despite the target(base) branches containing a leading 'ubuntu/' branch name.

Instead of exclusion filters, let's give inclusion filters a pass to ensure we only run these workflows on main or other versioned upstream release branches of the format: 26.1, 26.1.1 or 26.1.x.

Because we are seeing ignore-branches exclusion filters being ignored on #6740, let's instead limit runs via the branches: inclusion filter.

Proposed Commit Message

ci: use branches inclusion instead of branches-ignore exclusion

We have seen our branches-ignore still trigger gh-cla, alternate
distro and integration tests despite the target(base) branches
containing a leading 'ubuntu/' branch name.

Instead of exclusion filters, let's give inclusion filters a pass
to ensure we only run these workflows on main or other versioned
upstream release  branches of the format: 26.1, 26.1.1 or 26.1.x.

Additional Context

#6740

Test Steps

This won't be active until it merges into upstream/ubuntu/noble for any subsequent PRs because the original workflow in the base/target branch is what should be run when active Pull requests trigger the event.

Merge type

• Squash merge using "Proposed Commit Message"
• Rebase and merge unique commits. Requires commit messages per-commit each referencing the pull request number (#<PR_NUM>)