Bump Moq from 4.20.72 to 4.21.0

---
updated-dependencies:
- dependency-name: Moq
  dependency-version: 4.21.0
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

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

Author: dependabot[bot]

tests/Microsoft.Graph.DotnetCore.Test/Microsoft.Graph.DotnetCore.Test.csproj

@@ -17,7 +17,7 @@
 
   <ItemGroup>
     <PackageReference Include="Microsoft.NET.Test.Sdk" Version="18.5.1" />
-    <PackageReference Include="Moq" Version="4.20.72" />
+    <PackageReference Include="Moq" Version="4.21.0" />
     <PackageReference Include="xunit" Version="2.9.3" />
     <PackageReference Include="xunit.runner.visualstudio" Version="3.1.5">
       <PrivateAssets>all</PrivateAssets>