[wasm] Fix runtime tests build on CI (dotnet#93646)

* [wasm] Fix runtime tests build on CI

Runtime tests build for wasm started timing out recently, with the job
getting cancelled, likely due to the build hitting the container limits.

This changes the inner test builds to not run in parallel at all, with
`/m:1`, which unblocks the CI at least.

Issue: dotnet#93134

* Disable runtime tests that require native libraries, which are not currently built for wasm

src/tests/build.proj

@@ -589,7 +589,9 @@
       <GroupBuildCmd>$(GroupBuildCmd) "/p:__TestGroupToBuild=$(__TestGroupToBuild)"</GroupBuildCmd>
       <GroupBuildCmd>$(GroupBuildCmd) "/p:__SkipRestorePackages=1"</GroupBuildCmd>
       <GroupBuildCmd>$(GroupBuildCmd) /nodeReuse:false</GroupBuildCmd>
-      <GroupBuildCmd>$(GroupBuildCmd) /maxcpucount</GroupBuildCmd>
+      <GroupBuildCmd Condition="'$(TargetOS)' != 'browser' or '$(ContinuousIntegrationBuild)' != 'true'">$(GroupBuildCmd) /maxcpucount</GroupBuildCmd>
+      <!-- https://github.com/dotnet/runtime/issues/93134 -->
+      <GroupBuildCmd Condition="'$(TargetOS)' == 'browser' and '$(ContinuousIntegrationBuild)' == 'true'">$(GroupBuildCmd) /m:1</GroupBuildCmd>
       <GroupBuildCmd Condition="'$(TargetOS)' == 'ios' or '$(TargetOS)' == 'tvos'">$(GroupBuildCmd) "/p:DevTeamProvisioning=-"</GroupBuildCmd>
       <GroupBuildCmd>$(GroupBuildCmd) /bl:$(ArtifactsDir)/log/$(Configuration)/InnerManagedTestBuild.$(__TestGroupToBuild).binlog</GroupBuildCmd>
       <GroupBuildCmd Condition="'$(CrossBuild)' == 'true'">$(GroupBuildCmd) "/p:CrossBuild=true"</GroupBuildCmd>

src/tests/issues.targets

@@ -2835,7 +2835,6 @@
         </ExcludeList>
     </ItemGroup>
 
-
     <ItemGroup Condition="'$(TargetArchitecture)' == 'wasm' or '$(TargetsAppleMobile)' == 'true'">
         <ExcludeList Include="$(XunitTestBinBase)/baseservices/finalization/CriticalFinalizer/**">
             <Issue>https://github.com/dotnet/runtime/issues/75756</Issue>
@@ -3272,6 +3271,9 @@
         <ExcludeList Include="$(XunitTestBinBase)/tracing/eventpipe/gcdump/**">
             <Issue>System.Diagnostics.Process is not supported on wasm</Issue>
         </ExcludeList>
+        <ExcludeList Include = "$(XunitTestBinBase)/Interop/PInvoke/Vector2_3_4/Vector2_3_4/**">
+            <Issue>needs native libraries</Issue>
+        </ExcludeList>
     </ItemGroup>
 
     <ItemGroup Condition="'$(TargetOS)' == 'android'" >