Use SHA for action versions

Author: mwcraig

.github/workflows/publish.yml

@@ -25,12 +25,12 @@ jobs:
     runs-on: ubuntu-latest
 
     steps:
-      - uses: actions/checkout@v4
+      - uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683  # 4.2.2
 
       - name: Build wheel and sdist
         run: pipx run build
 
-      - uses: actions/upload-artifact@v4
+      - uses: actions/upload-artifact@ea165f8d65b6e75b540449e92b4886f43607fa02  # 4.6.2
         with:
           name: wheel-sdist
           path: dist/*
@@ -44,11 +44,11 @@ jobs:
     # or, alternatively, upload to PyPI on every tag starting with 'v' (remove on: release above to use this)
     # if: github.event_name == 'push' && startsWith(github.ref, 'refs/tags/v')
     steps:
-      - uses: actions/download-artifact@v4
+      - uses: actions/download-artifact@d3f86a106a0bac45b974a628896c90dbdf5c8093  # 4.3.0
         with:
           # unpacks all CIBW artifacts into dist/
           pattern: wheel-sdist
           path: dist
           merge-multiple: true
 
-      - uses: pypa/gh-action-pypi-publish@release/v1
+      - uses: pypa/gh-action-pypi-publish@76f52bc884231f62b9a034ebfe128415bbaabdfc  # 1.12.4