fix(ci): update .main.commit for non-dev mcore branches - #3213

Summary

• When bumping on release branches (e.g. r0.4.0 with mcore-branch=mcore-core_r0.17.0), the mcore-branch input matches neither "main" nor "dev", so .main.commit was never written
• The unit test test_main_commit_matches_submodule then fails because the bumped submodule commit no longer matches .main.commit
• Fix: write .main.commit for all non-dev branches (covers both main and release branches)

Before:

if [[ "$TARGET_BRANCH" == "main" ]]; then
    echo $MLM_COMMIT > .main.commit
elif [[ "$TARGET_BRANCH" == "dev" ]]; then
    echo $MLM_COMMIT > .dev.commit
fi

After:

if [[ "$TARGET_BRANCH" == "dev" ]]; then
    echo $MLM_COMMIT > .dev.commit
else
    echo $MLM_COMMIT > .main.commit
fi

Test plan

• Verify test_main_commit_matches_submodule passes on next bump run for r0.4.0

Summary by CodeRabbit

Release Notes

• Chores
  • Updated internal dependency management workflow to improve commit tracking across different release branches.

Note: This release contains only internal infrastructure improvements with no direct impact on end-user functionality.