Update GitHub Actions and README.md docs

- Downgraded `actions/checkout` and `actions/setup-dotnet` in `dotnet.yml` to v3 and configured for .NET 8.0.x.
- Simplified .NET build process by combining build and test steps.
- Enhanced `README.md` for `XperienceCommunity.OutputCache` with improved example formatting.

.github/workflows/dotnet.yml

@@ -15,14 +15,12 @@ jobs:
     runs-on: ubuntu-latest
 
     steps:
-    - uses: actions/checkout@v4
+    - uses: actions/checkout@v3
     - name: Setup .NET
-      uses: actions/setup-dotnet@v4
+      uses: actions/setup-dotnet@v3
       with:
         dotnet-version: 8.0.x
     - name: Restore dependencies
       run: dotnet restore
     - name: Build
-      run: dotnet build --no-restore
-    - name: Test
-      run: dotnet test --no-build --verbosity normal
+      run: dotnet build --no-restore

README.md

@@ -73,12 +73,11 @@ Output caching is now enabled for your application. The library will automatical
 To add output caching to your views, use the `OutputCache` attribute on your controller actions:
 
     ```csharp
-
-        [OutputCache(PolicyName = "KenticoPolicy")]
-        public async Task<IActionResult> Index()
-        {
-            return View();
-        }
+    [OutputCache(PolicyName = "KenticoPolicy")]
+    public async Task<IActionResult> Index()
+    {
+        return View();
+    }
     ```