Add UseDotNet prerequisite for PublishCodeCoverageResults@2

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

Author: Abel Milash

.azdo/ci-pr.yaml

@@ -81,6 +81,11 @@ extends:
             testRunTitle: 'Python 3.12'
           displayName: 'Publish test results'
 
+        - task: UseDotNet@2
+          inputs:
+            version: '8.x'
+          displayName: 'Install .NET (required by PublishCodeCoverageResults@2)'
+
         - task: PublishCodeCoverageResults@2
           condition: succeededOrFailed()
           inputs: