Update actions/checkout action from v6.0.3 to v7.0.0

Author: renovate[bot]

.github/workflows/flate.yaml

@@ -20,7 +20,7 @@ jobs:
       contents: read
     steps:
       - name: Checkout
-        uses: actions/checkout@df4cb1c069e1874edd31b4311f1884172cec0e10 # v6.0.3
+        uses: actions/checkout@9c091bb21b7c1c1d1991bb908d89e4e9dddfe3e0 # v7.0.0
         with:
           fetch-depth: 0
           persist-credentials: false
@@ -40,7 +40,7 @@ jobs:
       contents: read
     steps:
       - name: Checkout
-        uses: actions/checkout@df4cb1c069e1874edd31b4311f1884172cec0e10 # v6.0.3
+        uses: actions/checkout@9c091bb21b7c1c1d1991bb908d89e4e9dddfe3e0 # v7.0.0
         with:
           fetch-depth: 0
           persist-credentials: false