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

Author: renovate[bot]

.github/workflows/publish-to-nuget.yml

@@ -22,7 +22,7 @@ jobs:
           dotnet-version: 10.0.x
 
       - name: Cache NuGet packages
-        uses: actions/cache@v5
+        uses: actions/cache@v6
         with:
           path: ~/.nuget/packages
           key: ${{ runner.os }}-nuget-${{ hashFiles('**/packages.lock.json') }}