Update upload-artifact action to version 4 in buildtest workflow (#1615)

* Update upload-artifact action to version 4 in buildtest workflow

* Disable parallel build for E2E tests in buildtest workflow

* Update artifact name to include OS in buildtest workflow

Author: tg123

.github/workflows/buildtest.yaml

@@ -31,9 +31,9 @@ jobs:
           directory: ./TestResults
           files: '*.cobertura.xml'
       - name: Upload test results
-        uses: actions/upload-artifact@v3
+        uses: actions/upload-artifact@v4
         with:
-          name: test-results
+          name: test-results-${{ matrix.os }}
           path: ./TestResults
         if: ${{ always() }} # Always run this step even on failure
 
@@ -73,7 +73,7 @@ jobs:
       - name: Test
         run: |
           true > skip.log
-          env K8S_E2E_MINIKUBE=1 dotnet test tests/E2E.Tests --logger "SkipTestLogger;file=$PWD/skip.log"
+          env K8S_E2E_MINIKUBE=1 dotnet test tests/E2E.Tests --logger "SkipTestLogger;file=$PWD/skip.log" -p:BuildInParallel=false
           if [ -s skip.log ]; then
             cat skip.log
             echo "CASES MUST NOT BE SKIPPED"
@@ -82,7 +82,7 @@ jobs:
       - name: AOT Test
         run: |
           true > skip.log
-          env K8S_E2E_MINIKUBE=1 dotnet test tests/E2E.Aot.Tests --logger "SkipTestLogger;file=$PWD/skip.log"
+          env K8S_E2E_MINIKUBE=1 dotnet test tests/E2E.Aot.Tests --logger "SkipTestLogger;file=$PWD/skip.log" -p:BuildInParallel=false
           if [ -s skip.log ]; then
             cat skip.log
             echo "CASES MUST NOT BE SKIPPED"