chore(deps): update github actions to df4cb1c (#74)

Author: renovate-bot

.github/workflows/header-check.yml

@@ -24,7 +24,7 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - name: 'Checkout Repository'
-        uses: actions/checkout@de0fac2e4500dabe0009e67214ff5f5447ce83dd # v6
+        uses: actions/checkout@df4cb1c069e1874edd31b4311f1884172cec0e10 # v6
 
       - name: Check License Header
         uses: apache/skywalking-eyes/header@61275cc80d0798a405cb070f7d3a8aaf7cf2c2c1 # v0.8.0

.github/workflows/json-lint.yml

@@ -23,7 +23,7 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - name: Check out code
-        uses: actions/checkout@de0fac2e4500dabe0009e67214ff5f5447ce83dd # v6
+        uses: actions/checkout@df4cb1c069e1874edd31b4311f1884172cec0e10 # v6
 
       - name: Run JSON Lint
         run: jq . gemini-extension.json

.github/workflows/markdown-checks.yml

@@ -24,7 +24,7 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - name: Check out code
-        uses: actions/checkout@de0fac2e4500dabe0009e67214ff5f5447ce83dd # v6
+        uses: actions/checkout@df4cb1c069e1874edd31b4311f1884172cec0e10 # v6
 
       - name: Link Checker
         uses: lycheeverse/lychee-action@8646ba30535128ac92d33dfc9133794bfdd9b411 # v2.8.0

.github/workflows/package-and-upload-assets.yml

@@ -39,7 +39,7 @@ jobs:
 
     steps:
       - name: Checkout code at the new tag
-        uses: actions/checkout@de0fac2e4500dabe0009e67214ff5f5447ce83dd # v6
+        uses: actions/checkout@df4cb1c069e1874edd31b4311f1884172cec0e10 # v6
         with:
           ref: ${{ github.event.release.tag_name }}
 
@@ -117,7 +117,7 @@ jobs:
       contents: write
     steps:
       - name: Checkout code
-        uses: actions/checkout@de0fac2e4500dabe0009e67214ff5f5447ce83dd # v6
+        uses: actions/checkout@df4cb1c069e1874edd31b4311f1884172cec0e10 # v6
 
       - name: Download all archives from workflow artifacts
         uses: actions/download-artifact@3e5f45b2cfb9172054b4087a40e8e0b5a5461e7c # v8

.github/workflows/presubmit-tests.yml

@@ -22,7 +22,7 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - name: Check out code
-        uses: actions/checkout@de0fac2e4500dabe0009e67214ff5f5447ce83dd # v6
+        uses: actions/checkout@df4cb1c069e1874edd31b4311f1884172cec0e10 # v6
 
       - name: Install Gemini CLI
         run: npm install @google/gemini-cli