chore(deps): bump coverlet.msbuild from 2.9.0 to 6.0.2 in /FirebaseAdmin (#402)

Author: dependabot[bot]

FirebaseAdmin/FirebaseAdmin.Tests/FirebaseAdmin.Tests.csproj

@@ -11,7 +11,7 @@
   </PropertyGroup>
 
   <ItemGroup>
-    <PackageReference Include="coverlet.msbuild" Version="2.9.0">
+    <PackageReference Include="coverlet.msbuild" Version="6.0.2">
       <PrivateAssets>all</PrivateAssets>
       <IncludeAssets>runtime; build; native; contentfiles; analyzers; buildtransitive</IncludeAssets>
     </PackageReference>