[ci]Remove multiprocessor build to temporarily fix arm64 build issues(#21930)

Co-authored-by: Clint Rutkas <clint@rutkas.com>

.pipelines/ci/templates/build-powertoys-ci.yml

@@ -1,7 +1,7 @@
 parameters:
   configuration: 'Release'
   platform: ''
-  additionalBuildArguments: '-m'
+  additionalBuildArguments: '-m:2'
 
 jobs:
 - job: Build${{ parameters.platform }}${{ parameters.configuration }}

.pipelines/ci/templates/build-powertoys-steps.yml

@@ -71,7 +71,7 @@ steps:
     platform: '$(BuildPlatform)'
     configuration: '$(BuildConfiguration)'
     msbuildArgs: ${{ parameters.additionalBuildArguments }}
-    maximumCpuCount: true
+    maximumCpuCount: false # Multi processor build for arm64 is broken in the latest pipelines update
 
 - task: NuGetCommand@2
   displayName: Restore NuGet packages for BugReportTool.sln