Update Build Wheels to only build once on RCs (#32009)

.github/workflows/build_wheels.yml

@@ -236,6 +236,7 @@ jobs:
  arch: aarch64
  steps:
  - name: Download python source distribution from artifacts
+ if: ${{ needs.build_source.outputs.is_rc == 0 }}
  # Pinned to v3 because of https://github.com/actions/download-artifact/issues/249
  uses: actions/download-artifact@v3
  with:
@@ -259,6 +260,7 @@ jobs:
  # note: sync cibuildwheel version with gradle task sdks:python:bdistPy* steps
  run: pip install cibuildwheel==2.17.0 setuptools
  - name: Build wheel
+ if: ${{ needs.build_source.outputs.is_rc == 0 }}
  working-directory: apache-beam-source
  env:
  CIBW_BUILD: ${{ matrix.os_python.python }}
@@ -271,13 +273,15 @@ jobs:
  if: startsWith(matrix.os_python.os, 'macos')
  run: brew install coreutils
  - name: Add checksums
+ if: ${{ needs.build_source.outputs.is_rc == 0 }}
  working-directory: apache-beam-source/wheelhouse/
  run: |
  for file in *.whl; do
  sha512sum $file > ${file}.sha512
  done
  shell: bash
  - name: Upload wheels as artifacts
+ if: ${{ needs.build_source.outputs.is_rc == 0 }}
  # Pinned to v3 because of https://github.com/actions/download-artifact/issues/249
  uses: actions/upload-artifact@v3
  with: