Update actions/checkout digest to df4cb1c (#33738)

Co-authored-by: renovate[bot] <29139614+renovate[bot]@users.noreply.github.com>

.github/workflows/tests.yml

@@ -43,7 +43,7 @@ jobs:
               run: df -h && df -i
 
             - name: Checkout code
-              uses: actions/checkout@de0fac2e4500dabe0009e67214ff5f5447ce83dd # v6
+              uses: actions/checkout@df4cb1c069e1874edd31b4311f1884172cec0e10 # v6
               with:
                   repository: ${{ inputs.matrix-js-sdk-sha && 'element-hq/element-web' || github.repository }}
                   persist-credentials: false
@@ -112,7 +112,7 @@ jobs:
         runs-on: ubuntu-24.04
         steps:
             - name: Checkout code
-              uses: actions/checkout@de0fac2e4500dabe0009e67214ff5f5447ce83dd # v6
+              uses: actions/checkout@df4cb1c069e1874edd31b4311f1884172cec0e10 # v6
               with:
                   repository: ${{ inputs.matrix-js-sdk-sha && 'element-hq/element-web' || github.repository }}
                   persist-credentials: false
@@ -193,7 +193,7 @@ jobs:
                   target_url: https://github.com/${{ github.repository }}/actions/runs/${{ github.run_id }}
 
             - name: Checkout code
-              uses: actions/checkout@de0fac2e4500dabe0009e67214ff5f5447ce83dd # v6
+              uses: actions/checkout@df4cb1c069e1874edd31b4311f1884172cec0e10 # v6
               if: needs.jest_ew.result == 'success' && needs.vitest.result == 'success' && env.ENABLE_COVERAGE == 'true'
               with:
                   persist-credentials: false