[CI] Outerloop/Quarantined workflows - build only the required bits

The `build solution` step in `Generate runsheet` job was running out of
space. The agent starts with around 22G free.

After the changes here to limit the build to only the test jobs:

- the disk has 5.3G free after the build
- The build time goes down from ~7 mins to ~4 mins.

Fixes #12143

Author: radical

.github/workflows/specialized-test-runner.yml

@@ -36,16 +36,23 @@ jobs:
     steps:
       - uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4.2.2
 
-      # We need to build the whole solution, so that we can interrogate each test project
+      - name: Show disk usage before build
+        run: |-
+          df -h
+          du -sh ${{ github.workspace }}
+
+      # We need to build test projects, so that we can interrogate each test project
       # and find out whether it contains any tests of the specified type.
+      # We use BuildTestsOnly=true to reduce disk space usage by skipping src, playground, and pack projects.
       - name: Build the solution
         run: >
           ./build.sh
           --restore
           --build
           -c Release
+          /p:BuildTestsOnly=true
           /p:GeneratePackageOnBuild=false
-          ${{ !inputs.enablePlaywrightInstall && '/p:InstallBrowsersForPlaywright=false' || '' }}
+          /p:InstallBrowsersForPlaywright=false
 
       - name: Generate test runsheet
         id: generate_tests_matrix
@@ -59,8 +66,17 @@ jobs:
           -c Release
           /p:Restore=false
           /p:Build=false
+          /p:InstallBrowsersForPlaywright=false
           /bl:${{ github.workspace }}/artifacts/log/Release/runsheet.binlog
 
+      - name: Show disk usage after build
+        if: ${{ always() }}
+        run: |-
+          df -h
+          du -d 1 h ~/.nuget/packages
+          du -d 1 -h ${{ github.workspace }}
+          du -d 1 -h ${{ github.workspace }}/artifacts
+
       - name: Upload logs, and test results
         if: ${{ always() }}
         uses: actions/upload-artifact@4cec3d8aa04e39d1a68397de0c4cd6fb9dce8ec1 # v4.6.1

eng/Build.props

@@ -1,4 +1,14 @@
 <Project TreatAsLocalProperty="TargetRids">
+  <!--
+    Properties:
+      SkipManagedBuild - if 'true', skips building all managed projects, defaults to 'false'
+      SkipNativeBuild  - if 'true', skips building all native projects, defaults to 'false'
+      BuildExtension   - if 'true', builds the extension project, defaults to 'false'
+      BuildTestsOnly   - if 'true', builds only test projects, defaults to 'false'
+      SkipTestProjects - if 'true', skips building test projects, defaults to 'false'
+      TargetRids       - colon separated list of RIDs to build native projects for
+  -->
+
   <PropertyGroup>
     <BuildRid>$([System.Runtime.InteropServices.RuntimeInformation]::RuntimeIdentifier)</BuildRid>
 
@@ -7,7 +17,10 @@
     <TargetRids Condition="'$(TargetRids)' == ''">$(BuildRid)</TargetRids>
   </PropertyGroup>
 
-  <ItemGroup Condition="'$(SkipManagedBuild)' != 'true'">
+  <!-- `$(BuildTestsOnly)` allows building only test projects, skipping src, playground,
+        and pack projects. This is useful for reducing disk space usage when only test
+        projects need to be built, such as during test runsheet generation. -->
+  <ItemGroup Condition="'$(SkipManagedBuild)' != 'true' and '$(BuildTestsOnly)' != 'true'">
     <!-- Project name validation runs once in the outer build -->
     <ProjectToBuild Include="$(RepoRoot)eng\OuterPreBuild.proj" />
 
@@ -16,11 +29,13 @@
     <ProjectToBuild Include="$(RepoRoot)eng\dashboardpack\**\*.csproj" />
 
     <ProjectToBuild Include="$(RepoRoot)playground\**\*.csproj" />
+  </ItemGroup>
 
-    <!-- `$(SkipTestProjects)` allows skipping test projects from being
-          included in the build at all. This is useful for cases like when we are
-          just building the packages, and don't need to build the test projects. -->
-    <ProjectToBuild Include="$(RepoRoot)tests\**\*.csproj" Condition="'$(SkipTestProjects)' != 'true'" />
+  <!-- `$(SkipTestProjects)` allows skipping test projects from being
+        included in the build at all. This is useful for cases like when we are
+        just building the packages, and don't need to build the test projects. -->
+  <ItemGroup Condition="'$(SkipManagedBuild)' != 'true' and '$(SkipTestProjects)' != 'true'">
+    <ProjectToBuild Include="$(RepoRoot)tests\**\*.csproj" />
   </ItemGroup>
 
   <!-- Extension build project -->