merge-queue: golangci-lint doesn't filter to only new issues

[dmihalcik-virtru]

See: golangci/golangci-lint-action#956

The action's only-new-issues feature does not handle the merge_group event, falling back to list all issues for merge queue runs.

Sample run: https://github.com/opentdf/platform/actions/runs/8101523724/job/22141898894

Work around: Use the command line --new-from-rev=main instead, on merge queue events. This should give (about) all changes between main and the current request. Alternative: --new-from-rev=HEAD~1 or I think just --new? Which would give diffs against the most earlier item currently in the queue, but that might be less stable?