chore(deps): update actions/setup-python action to v4 (GoogleCloudPlatform#380)

Author: renovate-bot

.github/workflows/coverage.yml

@@ -20,7 +20,7 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - name: Setup Python
-        uses: actions/setup-python@v3
+        uses: actions/setup-python@v4
         with:
           python-version: "3.10"
       - run: pip install nox coverage

.github/workflows/lint.yml

@@ -21,7 +21,7 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - name: Setup Python
-        uses: actions/setup-python@v3
+        uses: actions/setup-python@v4
         with:
           python-version: "3.10"
 

.github/workflows/tests.yml

@@ -30,7 +30,7 @@ jobs:
       fail-fast: false
     steps:
       - name: Setup Python ${{ matrix.python-version }}
-        uses: actions/setup-python@v3
+        uses: actions/setup-python@v4
         with:
           python-version: ${{ matrix.python-version }}