🔼 Update actions/checkout action to v6

Author: renovate[bot]

.github/workflows/build.yml

@@ -25,7 +25,7 @@ jobs:
         shell: bash
 
     steps:
-      - uses: actions/checkout@v5
+      - uses: actions/checkout@v6
 
       - name: Setup dotnet
         uses: actions/setup-dotnet@v5

.github/workflows/release.yml

@@ -18,7 +18,7 @@ jobs:
         shell: bash
 
     steps:
-      - uses: actions/checkout@v5
+      - uses: actions/checkout@v6
 
       - name: Setup dotnet
         uses: actions/setup-dotnet@v5