chore: bump MSTest from 3.6.4 to 3.7.0 in /src

Bumps [MSTest](https://github.com/microsoft/testfx) from 3.6.4 to 3.7.0.
- [Release notes](https://github.com/microsoft/testfx/releases)
- [Changelog](https://github.com/microsoft/testfx/blob/main/docs/Changelog.md)
- [Commits](microsoft/testfx@v3.6.4...v3.7.0)

---
updated-dependencies:
- dependency-name: MSTest
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

Signed-off-by: dependabot[bot] <[email protected]>

src/Nager.KeyValueParser.UnitTest/Nager.KeyValueParser.UnitTest.csproj

@@ -9,7 +9,7 @@
 
   <ItemGroup>
     <PackageReference Include="Microsoft.NET.Test.Sdk" Version="17.12.0" />
-    <PackageReference Include="MSTest" Version="3.6.4" />
+    <PackageReference Include="MSTest" Version="3.7.0" />
   </ItemGroup>
 
   <ItemGroup>