CI: Run build-wheel if [build wheels] is in commit message

Author: effigies

.github/workflows/wheels.yml

@@ -30,6 +30,7 @@ jobs:
   build-wheel:
     name: Build wheel for ${{ matrix.python }}-${{ matrix.buildplat[1] }}
     runs-on: ${{ matrix.buildplat[0] }}
+    if: github.event_name == 'push' && startsWith(github.ref, 'refs/tags/') || contains(github.event.head_commit.message, '[build wheels]')
     strategy:
       fail-fast: false
       matrix: