Enable caching of pip dependencies

PiperOrigin-RevId: 578740011

.github/workflows/test_python.yml

@@ -76,6 +76,7 @@ jobs:
         with:
           python-version: ${{ matrix.version }}
           cache: pip
+          cache-dependency-path: 'python/requirements.txt'
 
       - name: Validate version
         run: python3 --version | grep ${{ matrix.version }} || (echo "Invalid Python version - $(python3 --version)" && exit 1)

.github/workflows/test_upb.yml

@@ -70,6 +70,10 @@ jobs:
         uses: protocolbuffers/protobuf-ci/checkout@v2
         with:
           ref: ${{ inputs.safe-checkout }}
+      - uses: actions/setup-python@61a6322f88396a6271a6ee3565807d608ecaddd1 # v4.7.0
+        with:
+          cache: pip
+          cache-dependency-path: 'python/requirements.txt'
       - name: Run tests
         uses: protocolbuffers/protobuf-ci/bazel@v2
         with:
@@ -92,6 +96,10 @@ jobs:
         uses: protocolbuffers/protobuf-ci/checkout@v2
         with:
           ref: ${{ inputs.safe-checkout }}
+      - uses: actions/setup-python@61a6322f88396a6271a6ee3565807d608ecaddd1 # v4.7.0
+        with:
+          cache: pip
+          cache-dependency-path: 'python/requirements.txt'
       - name: Run tests
         uses: protocolbuffers/protobuf-ci/bazel@v2
         with:
@@ -195,7 +203,7 @@ jobs:
         with:
           name: requirements
           path: requirements
-      - uses: actions/setup-python@v2
+      - uses: actions/setup-python@61a6322f88396a6271a6ee3565807d608ecaddd1 # v4.7.0
         with:
           python-version: ${{ matrix.python-version }}
           architecture: ${{ matrix.architecture }}
@@ -250,7 +258,7 @@ jobs:
           path: wheels
       - name: Delete Binary Wheels
         run: find wheels -type f | grep -v none-any | xargs rm
-      - uses: actions/setup-python@v2
+      - uses: actions/setup-python@61a6322f88396a6271a6ee3565807d608ecaddd1 # v4.7.0
         with:
           python-version: ${{ matrix.python-version }}
       - name: Setup Python venv