Bump Microsoft.NET.Test.Sdk from 18.0.1 to 18.3.0

---
updated-dependencies:
- dependency-name: Microsoft.NET.Test.Sdk
  dependency-version: 18.3.0
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

Signed-off-by: dependabot[bot] <support@github.com>

Author: dependabot[bot]

stdc.Tests/stdc.Tests.csproj

@@ -13,7 +13,7 @@
       <PrivateAssets>all</PrivateAssets>
     </PackageReference>
     <PackageReference Include="NUnit3TestAdapter" Version="6.1.0" />
-    <PackageReference Include="Microsoft.NET.Test.Sdk" Version="18.0.1" />
+    <PackageReference Include="Microsoft.NET.Test.Sdk" Version="18.3.0" />
   </ItemGroup>
 
   <ItemGroup>