Pin (and upgrade) immutable-eligible action actions/setup-python to their semantic versions

Author: mrecachinas

.github/workflows/python-ci.yml

@@ -22,7 +22,7 @@ jobs:
     steps:
       - uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4.2.2
       - name: Set up Python ${{ matrix.python-version }}
-        uses: actions/setup-python@0b93645e9fea7318ecaed2b359559ac225c90a2b # v5.3.0
+        uses: actions/setup-python@5.3.0
         with:
           python-version: ${{ matrix.python-version }}
       - name: Install dependencies