Update actions/checkout action to v6.0.3

Author: renovate[bot]

.github/workflows/copilot-setup-steps.yml

@@ -26,7 +26,7 @@ jobs:
     # You can define any steps you want, and they will run before the agent starts.
     # If you do not check out your code, Copilot will do this for you.
     steps:
-    - uses: actions/checkout@de0fac2e4500dabe0009e67214ff5f5447ce83dd # v6.0.2
+    - uses: actions/checkout@df4cb1c069e1874edd31b4311f1884172cec0e10 # v6.0.3
       with:
         fetch-depth: 0 # avoid shallow clone so nbgv can do its work.
     - name: ⚙ Install prerequisites

.github/workflows/docs.yml

@@ -24,7 +24,7 @@ jobs:
       url: ${{ steps.deployment.outputs.page_url }}
     runs-on: ubuntu-latest
     steps:
-    - uses: actions/checkout@de0fac2e4500dabe0009e67214ff5f5447ce83dd # v6.0.2
+    - uses: actions/checkout@df4cb1c069e1874edd31b4311f1884172cec0e10 # v6.0.3
       with:
         fetch-depth: 0 # avoid shallow clone so nbgv can do its work.
     - name: ⚙ Install prerequisites

.github/workflows/docs_validate.yml

@@ -13,7 +13,7 @@ jobs:
     name: 📚 Doc validation
     runs-on: ubuntu-24.04
     steps:
-    - uses: actions/checkout@de0fac2e4500dabe0009e67214ff5f5447ce83dd # v6.0.2
+    - uses: actions/checkout@df4cb1c069e1874edd31b4311f1884172cec0e10 # v6.0.3
       with:
         fetch-depth: 0 # avoid shallow clone so nbgv can do its work.
     - name: 🔗 Markup Link Checker (mlc)

.github/workflows/libtemplate-update.yml

@@ -17,7 +17,7 @@ jobs:
       contents: write
       pull-requests: write
     steps:
-    - uses: actions/checkout@de0fac2e4500dabe0009e67214ff5f5447ce83dd # v6.0.2
+    - uses: actions/checkout@df4cb1c069e1874edd31b4311f1884172cec0e10 # v6.0.3
       with:
         fetch-depth: 0 # avoid shallow clone so nbgv can do its work.