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

Author: renovate[bot]

.github/workflows/nuget-push.yml

@@ -13,7 +13,7 @@ jobs:
     runs-on: windows-latest
 
     steps:
-      - uses: actions/checkout@v4
+      - uses: actions/checkout@v6
       - name: Setup .NET
         uses: actions/setup-dotnet@v4
         with:

.github/workflows/qodana-analyze.yml

@@ -11,7 +11,7 @@ jobs:
   qodana:
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v4
+      - uses: actions/checkout@v6
         with:
           fetch-depth: 0
       - name: "Qodana Scan"