Update azure-pipelines.yaml

Author: jpobst

build-tools/automation/azure-pipelines.yaml

@@ -21,7 +21,7 @@ variables:
   RunningOnCI: true
   Build.Configuration: Release
   MaxJdkVersion: 8
-  DotNetCoreVersion: 6.0.x
+  DotNetCoreVersion: 6.0.202
   1ESWindowsPool: AzurePipelines-EO
   1ESWindowsImage: AzurePipelinesWindows2022compliant
   1ESMacPool: Azure Pipelines