Marking experimental/unstable github actions as such

[LecrisUT]

Is your feature request related to a problem? Please describe.
I've opened a PR for a feature and was greeted with some test failures that are unrelated to the test.

Describe the solution you'd like
It would be good to mark some of the github actions as experimental. The method I've used is something like

jobs:
  tests:
    name: >
      Python ${{ matrix.python }}
      ${{ matrix.experimental && ' [🧪 Experimental]' || '' }}
    continue-on-error: ${{ matrix.experimental || false }}
    strategy:
      fail-fast: false
      matrix:
        python: [ 3.13, 3.14, 3.15 ]
        include:
          - python: 3.15
            experimental: true
  overall:
    needs: [ tests ]
    runs-on: ubuntu-slim
    steps:
        uses: re-actors/alls-green@release/v1
        with:
          jobs: ${{ toJSON(needs) }}
    if: always()

To break this down:

• name: to show it nicely in the checks view
• fail-fast + continue-on-error: to not block other jobs and not affect the overall job results
• re-actors/alls-green: to parse the state of the overall jobs with the above