Fix invalid GitHub Action versions blocking CI

.github/workflows/ci.yml

@@ -25,12 +25,12 @@ jobs:
       !contains(github.event.pull_request.labels.*.name, 'ci:skip-tests')
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v6
-      - uses: actions/setup-python@v6
+      - uses: actions/checkout@v4
+      - uses: actions/setup-python@v5
         with:
           python-version: '3.12'
           cache: 'pip'
-      - uses: astral-sh/setup-uv@v7
+      - uses: astral-sh/setup-uv@v5
         with:
           enable-cache: true
       - name: Install dependencies
@@ -58,12 +58,12 @@ jobs:
     runs-on: ubuntu-latest
     continue-on-error: true
     steps:
-      - uses: actions/checkout@v6
-      - uses: actions/setup-python@v6
+      - uses: actions/checkout@v4
+      - uses: actions/setup-python@v5
         with:
           python-version: '3.12'
           cache: 'pip'
-      - uses: astral-sh/setup-uv@v7
+      - uses: astral-sh/setup-uv@v5
         with:
           enable-cache: true
       - name: Install dependencies

.github/workflows/deploy-staging.yml

@@ -10,7 +10,7 @@ jobs:
     steps:
       - uses: actions/checkout@v4
       - name: Set up Python
-        uses: actions/setup-python@v4
+        uses: actions/setup-python@v5
         with:
           python-version: '3.11'
       - name: Deploy to staging

.github/workflows/gemini-review.yml

@@ -39,7 +39,7 @@ jobs:
           permission-pull-requests: 'write'
 
       - name: 'Checkout repository'
-        uses: 'actions/checkout@08c6903cd8c0fde910a37f88322edcfb5dd907a8' # ratchet:actions/checkout@v5
+        uses: 'actions/checkout@08c6903cd8c0fde910a37f88322edcfb5dd907a8' # ratchet:actions/checkout@v4
 
       - name: 'Run Gemini pull request review'
         uses: 'google-github-actions/run-gemini-cli@v0' # ratchet:exclude

.github/workflows/pr-check.yml

@@ -22,7 +22,7 @@ jobs:
 
     steps:
       - name: Checkout code
-        uses: actions/checkout@v6
+        uses: actions/checkout@v4
         with:
           fetch-depth: 0
 
@@ -59,17 +59,17 @@ jobs:
 
     steps:
       - name: Checkout code
-        uses: actions/checkout@v6
+        uses: actions/checkout@v4
         with:
           fetch-depth: 0
 
       - name: Set up Python
-        uses: actions/setup-python@v6
+        uses: actions/setup-python@v5
         with:
           python-version: '3.12'
 
       - name: Install uv
-        uses: astral-sh/setup-uv@v7
+        uses: astral-sh/setup-uv@v5
         with:
           enable-cache: true
           cache-dependency-glob: 'setup/pyproject.toml'
@@ -133,7 +133,7 @@ jobs:
     if: always()
     steps:
       - name: Checkout code
-        uses: actions/checkout@v6
+        uses: actions/checkout@v4
 
       - name: Download Python coverage
         uses: actions/download-artifact@v4

.github/workflows/push-check.yml

@@ -26,17 +26,17 @@ jobs:
 
     steps:
       - name: Checkout code
-        uses: actions/checkout@v6
+        uses: actions/checkout@v4
         with:
           fetch-depth: 0
 
       - name: Set up Python
-        uses: actions/setup-python@v6
+        uses: actions/setup-python@v5
         with:
           python-version: '3.12'
 
       - name: Install uv
-        uses: astral-sh/setup-uv@v7
+        uses: astral-sh/setup-uv@v5
         with:
           enable-cache: true
           cache-dependency-glob: 'setup/pyproject.toml'
@@ -57,17 +57,17 @@ jobs:
 
     steps:
       - name: Checkout code
-        uses: actions/checkout@v6
+        uses: actions/checkout@v4
         with:
           fetch-depth: 0
 
       - name: Set up Python
-        uses: actions/setup-python@v6
+        uses: actions/setup-python@v5
         with:
           python-version: '3.12'
 
       - name: Install uv
-        uses: astral-sh/setup-uv@v7
+        uses: astral-sh/setup-uv@v5
         with:
           enable-cache: true
           cache-dependency-glob: 'setup/pyproject.toml'