Ignore ReleaseStatic outputs and clean intermediates (microsoft#5848)

## Change
Copy the C++/WinRT method for keeping the build servers with plenty of
space by cleaning the intermediates after building each project. The
precompiled headers alone are several GBs.

Also adds `ReleaseStatic` outputs to the .gitignore.

Author: JohnMcPMS

.gitignore

@@ -17,6 +17,7 @@ settings.json
 [Dd]ebug/
 [Dd]ebugPublic/
 [Rr]elease/
+[Rr]elease[Ss]tatic/
 [Rr]eleases/
 x64/
 x86/

azure-pipelines.yml

@@ -118,7 +118,8 @@ jobs:
                     /p:AppxBundlePlatforms="$(buildPlatform)"
                     /p:AppxPackageDir="$(appxPackageDir)"
                     /p:AppxBundle=Always
-                    /p:UapAppxPackageBuildMode=SideloadOnly'
+                    /p:UapAppxPackageBuildMode=SideloadOnly
+                    /p:WingetCleanIntermediateFiles=true'
       maximumCpuCount: true
 
   - task: MSBuild@1

src/Directory.Build.props

@@ -26,5 +26,10 @@
   <!-- For C# -->
   <PropertyGroup Condition="'$(WinGetMacros)' != ''">
     <DefineConstants>$(WinGetMacros)$(DefineConstants)</DefineConstants>
-  </PropertyGroup>
+  </PropertyGroup>
+
+  <!-- To prevent build agents from running out of disk space, clean as we go. -->
+  <Target Name="CleanIntermediateFiles" AfterTargets="Build" Condition="'$(WingetCleanIntermediateFiles)'=='true'">
+    <RemoveDir Directories="$(IntDir)" />
+  </Target>
 </Project>