Update DotNET-build.yml

Author: followynne

.github/workflows/DotNET-build.yml

@@ -28,9 +28,22 @@ on:
 
 jobs:
   ubuntu-latest:
-    name: ubuntu-20.04
-    runs-on: ubuntu-20.04
-    steps:
+    name: ubuntu-latest
+    runs-on: ubuntu-latest
+    strategy:
+      matrix:
+        dotnet-version: [ '6.0.x', '7.0.x', '8.0.x']
+
+    steps:
+      - uses: actions/checkout@v4
+      - name: Setup dotnet ${{ matrix.dotnet-version }}
+        uses: actions/setup-dotnet@v4
+        with:
+          dotnet-version: ${{ matrix.dotnet-version }}
+      # You can test your matrix by printing the current dotnet version
+      - name: Display dotnet version
+        run: dotnet --version
+    
       - uses: actions/setup-java@v4
         with:
           distribution: 'temurin'