chore(deps): update actions/checkout action to v6

Author: renovate[bot]

.github/workflows/release.yaml

@@ -30,7 +30,7 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - name: 🧾 Checkout
-        uses: actions/checkout@v5
+        uses: actions/checkout@v6
         with:
           token: ${{ secrets.GH_BASIC }}
           lfs: true

.github/workflows/spellcheck.yaml

@@ -15,7 +15,7 @@ jobs:
       run:
         working-directory: '.'
     steps:
-      - uses: actions/checkout@v5
+      - uses: actions/checkout@v6
         name: 🧾 Checkout
 
       - uses: streetsidesoftware/cspell-action@v8

.github/workflows/tests.yaml

@@ -26,7 +26,7 @@ jobs:
         shell: bash
     steps:
       - name: 🧾 Checkout
-        uses: actions/checkout@v5
+        uses: actions/checkout@v6
 
       - name: 💽 Setup .NET SDK
         uses: actions/setup-dotnet@v5