set checkout actions to use v6.0.3

Author: camillecroft

.github/workflows/bump-version.yml

@@ -17,7 +17,7 @@ jobs:
           owner: ${{ github.repository_owner }}
           repositories: ${{ github.event.repository.name }}
 
-      - uses: actions/checkout@9c091bb21b7c1c1d1991bb908d89e4e9dddfe3e0 # v7.0.0
+      - uses: actions/checkout@df4cb1c069e1874edd31b4311f1884172cec0e10 # v6.0.3
         with:
           token: ${{ steps.app-token.outputs.token }}
 

.github/workflows/ci.yml

@@ -10,7 +10,7 @@ jobs:
   test:
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@9c091bb21b7c1c1d1991bb908d89e4e9dddfe3e0 # v7.0.0
+      - uses: actions/checkout@df4cb1c069e1874edd31b4311f1884172cec0e10 # v6.0.3
       - uses: astral-sh/setup-uv@fac544c07dec837d0ccb6301d7b5580bf5edae39 # v8.2.0
       - name: Run tests
         run: uv run pytest