[spack-stack github config] GitHub action ignore-paths and branch protection rules block some PR merges.

[eap]

In short, branch protection rules require all tests to run for a PR to be merged, but our test "ignore-paths" result in some categories of change not running tests. In this state, admins must merge affected pull requests.

The following paths are excluded from tests defined in ubuntu-ci-x86_64-gnu.yaml as well as the oneapi and oneapi-ifx variants of the same workflow.

  pull_request:
    paths-ignore:
      - 'configs/sites/**'
      - '!configs/sites/tier2/*.default/*'
      - '**.md'
      - '.github/CODEOWNERS'
      - '.github/pull_request_template.md'
      - '.github/ISSUE_TEMPLA

Our develop branch protection rules require all tests run with no exclusion (exclusion is not configurable at this level.

I'm filing this just for tracking and reference, we can find a fix for this after the 2.1 release.