chore(deps): update mstest monorepo to 3.6.4

Author: renovate[bot]

src/VSPackage.Tests/VSPackage.Tests.csproj

@@ -73,10 +73,10 @@
   </ItemGroup>
   <ItemGroup>
     <PackageReference Include="MSTest.TestAdapter">
-      <Version>3.6.0</Version>
+      <Version>3.6.4</Version>
     </PackageReference>
     <PackageReference Include="MSTest.TestFramework">
-      <Version>3.6.0</Version>
+      <Version>3.6.4</Version>
     </PackageReference>
   </ItemGroup>
   <Import Project="$(VSToolsPath)\TeamTest\Microsoft.TestTools.targets" Condition="Exists('$(VSToolsPath)\TeamTest\Microsoft.TestTools.targets')" />