all-checks job: use '!cancelled()' instead of 'always()' #120

The all-checks aggregate job added in #118 is gated with if: always(), in both pupmod pr_tests.yml templates:

• modules/profile/files/pupmod/_github/workflows/pr_tests.yml
• modules/profile/files/pupmod/_github/workflows/pr_tests.simp-simp.yml

always() also returns true when the workflow run itself is cancelled, so a superseded or manually cancelled PR run still schedules a runner for all-checks just to print cancelled for every dependency and fail. GitHub's expressions reference recommends if: ${{ !cancelled() }} for a job that should run regardless of its dependencies' success or failure. The skipped and failure handling in the job's jq step is unchanged by it.

Change both templates to if: ${{ !cancelled() }} and roll it out in the next sync session after 20261014-all-checks-job.