sln: do not use PCH on CI (#3106)

.pipelines/build-installer.cmd

@@ -2,4 +2,4 @@ cd /D "%~dp0"
 
 call "C:\Program Files (x86)\Microsoft Visual Studio\2019\Enterprise\Common7\Tools\VsDevCmd.bat" -arch=amd64 -host_arch=amd64 -winsdk=10.0.18362.0
 SET IsPipeline=1
-call msbuild ../installer/PowerToysSetup.sln /p:Configuration=Release /p:Platform=x64 || exit /b 1
+call msbuild ../installer/PowerToysSetup.sln /p:Configuration=Release /p:Platform=x64 /p:CIBuild=true || exit /b 1

.pipelines/build.cmd

@@ -1,6 +1,6 @@
 cd /D "%~dp0"
 
 call "C:\Program Files (x86)\Microsoft Visual Studio\2019\Enterprise\Common7\Tools\VsDevCmd.bat" -arch=amd64 -host_arch=amd64 -winsdk=10.0.18362.0
-call msbuild ../PowerToys.sln /p:Configuration=Release /p:Platform=x64 || exit /b 1
+call msbuild ../PowerToys.sln /p:Configuration=Release /p:Platform=x64 /p:CIBuild=true || exit /b 1
 SET PTRoot=..
 call "..\installer\PowerToysSetup\publish.cmd"

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

@@ -1,7 +1,7 @@
 parameters:
   configuration: 'Release'
   platform: ''
-  additionalBuildArguments: ''
+  additionalBuildArguments: '/p:CIBuild=true'
 
 jobs:
 - job: Build${{ parameters.platform }}${{ parameters.configuration }}

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

@@ -32,7 +32,6 @@ steps:
     platform: '$(BuildPlatform)'
     configuration: '$(BuildConfiguration)'
     msbuildArgs: ${{ parameters.additionalBuildArguments }}
-    clean: true
     maximumCpuCount: true
 
 - task: VSTest@2