Update actions/checkout action to v5

Author: renovate[bot]

.github/workflows/main.yml

@@ -37,7 +37,7 @@ jobs:
 
     steps:
       - name: Checkout
-        uses: actions/checkout@v4
+        uses: actions/checkout@v5
 
       - name: Verify encoding
         shell: pwsh

.github/workflows/nuget.yml

@@ -21,7 +21,7 @@ jobs:
       NUGET_PACKAGES: ${{ github.workspace }}/.github/nuget-packages
     steps:
       - name: Checkout
-        uses: actions/checkout@v4
+        uses: actions/checkout@v5
 
       - name: Read version from ref
         id: version