[release/3.1] Move off of expiring machine pools (#38534)

* Move off of expiring machine pools

* Use 10.15

* Skip test

* SkipOnCI

* Update FileWatcherTests.cs

Author: wtgodbe

.azure/pipelines/ci.yml

@@ -626,7 +626,7 @@ stages:
     parameters:
       condition: ne(variables['SkipTests'], 'true')
       jobName: MacOS_Test
-      jobDisplayName: "Test: macOS 10.14"
+      jobDisplayName: "Test: macOS 10.15"
       agentOs: macOS
       isTestingJob: true
       buildArgs: --all --test "/p:RunTemplateTests=false" $(_InternalRuntimeDownloadArgs)
@@ -778,7 +778,7 @@ stages:
           - Windows_Templates_Test
           - Windows_Test
         pool:
-          vmImage: vs2017-win2016
+          vmImage: windows-latest
         publishUsingPipelines: ${{ variables._PublishUsingPipelines }}
         enablePublishBuildArtifacts: true # publish artifacts/log files
 

.azure/pipelines/jobs/default-build.yml

@@ -89,7 +89,7 @@ jobs:
     # See https://github.com/dotnet/arcade/blob/master/Documentation/ChoosingAMachinePool.md
     pool:
       ${{ if eq(parameters.agentOs, 'macOS') }}:
-        vmImage: macOS-10.14
+        vmImage: macOS-10.15
       ${{ if eq(parameters.agentOs, 'Linux') }}:
         vmImage: ubuntu-18.04
       ${{ if eq(parameters.agentOs, 'Windows') }}:

src/Tools/dotnet-watch/test/FileWatcherTests.cs

@@ -93,9 +93,10 @@ await UsingTempDirectory(async dir =>
             });
         }
 
-        [Theory]
+        [ConditionalTheory]
         [InlineData(true)]
         [InlineData(false)]
+        [SkipOnCI]
         public async Task MoveFile(bool usePolling)
         {
             await UsingTempDirectory(async dir =>