[wasm] Try to work around NuGet-Migrations issue (#83833)

Works around a CI issue where we somehow can't access a named mutex and fails

Contributes to #80619

Author: steveisok

eng/testing/tests.browser.targets

@@ -97,9 +97,12 @@
     <_XHarnessArgs Condition="'$(_XHarnessTestsTimeout)' != ''   " >$(_XHarnessArgs) &quot;--timeout=$(_XHarnessTestsTimeout)&quot;</_XHarnessArgs>
     <_XHarnessArgs Condition="'$(WasmXHarnessArgsCli)' != ''"      >$(_XHarnessArgs) $(WasmXHarnessArgsCli)</_XHarnessArgs>
 
+    <!-- Works around https://github.com/dotnet/runtime/issues/80619 -->
+    <_NugetWorkAroundCommand>dotnet new console</_NugetWorkAroundCommand>
+
     <!-- There two flavors of WasmXHarnessArgs and WasmXHarnessMonoArgs, one is MSBuild property and the other is environment variable -->
-    <RunScriptCommand Condition="'$(OS)' != 'Windows_NT'">$HARNESS_RUNNER $(_XHarnessArgs) %24XHARNESS_ARGS %24WasmXHarnessArgs -- $(WasmXHarnessMonoArgs) %24WasmXHarnessMonoArgs $(_AppArgs) %24WasmTestAppArgs</RunScriptCommand>
-    <RunScriptCommand Condition="'$(OS)' == 'Windows_NT'">%HARNESS_RUNNER% $(_XHarnessArgs) %XHARNESS_ARGS% %WasmXHarnessArgs%  -- $(WasmXHarnessMonoArgs) %WasmXHarnessMonoArgs% $(_AppArgs) %WasmTestAppArgs%</RunScriptCommand>
+    <RunScriptCommand Condition="'$(OS)' != 'Windows_NT'">$(_NugetWorkAroundCommand) $(_ShellCommandSeparator) $HARNESS_RUNNER $(_XHarnessArgs) %24XHARNESS_ARGS %24WasmXHarnessArgs -- $(WasmXHarnessMonoArgs) %24WasmXHarnessMonoArgs $(_AppArgs) %24WasmTestAppArgs</RunScriptCommand>
+    <RunScriptCommand Condition="'$(OS)' == 'Windows_NT'">$(_NugetWorkAroundCommand) $(_ShellCommandSeparator) %HARNESS_RUNNER% $(_XHarnessArgs) %XHARNESS_ARGS% %WasmXHarnessArgs%  -- $(WasmXHarnessMonoArgs) %WasmXHarnessMonoArgs% $(_AppArgs) %WasmTestAppArgs%</RunScriptCommand>
   </PropertyGroup>
 
   <PropertyGroup Condition="'$(BuildAOTTestsOnHelix)' == 'true'">