ci(tools): update actions/checkout action to v6 (#13)

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

Author: renovate[bot]

.github/workflows/flake.yml

@@ -27,7 +27,7 @@ jobs:
             {"contents": "write"}
 
       - name: Checkout source
-        uses: actions/checkout@93cb6efe18208431cddfb8368fd83d5badbf9bfd # v5
+        uses: actions/checkout@1af3b93b6815bc44a9784bd300feb67ff0d1eeb3 # v6
         with:
           token: ${{ steps.token.outputs.token }}
 

.github/workflows/release.yml

@@ -27,7 +27,7 @@ jobs:
             {"contents": "write"}
 
       - name: Checkout source
-        uses: actions/checkout@93cb6efe18208431cddfb8368fd83d5badbf9bfd # v5
+        uses: actions/checkout@1af3b93b6815bc44a9784bd300feb67ff0d1eeb3 # v6
         with:
           token: ${{ steps.token.outputs.token }}
 

.github/workflows/testing.yml

@@ -22,7 +22,7 @@ jobs:
 
     steps:
       - name: Checkout source
-        uses: actions/checkout@93cb6efe18208431cddfb8368fd83d5badbf9bfd # v5
+        uses: actions/checkout@1af3b93b6815bc44a9784bd300feb67ff0d1eeb3 # v6
 
       - name: Lint yaml
         uses: actionhippie/yamllint@1e187a11c123bb3c018c030fbe81168843d5ad17 # v1