Bump Verify.NUnit from 20.1.0 to 20.1.1 in /src (#901)

Author: dependabot[bot]

src/NugetUsage/NUnitNugetUsage/NUnitNugetUsage.csproj

@@ -8,7 +8,7 @@
     <PackageReference Include="Microsoft.NET.Test.Sdk" Version="17.6.0" />
     <PackageReference Include="NUnit" Version="3.13.3" />
     <PackageReference Include="NUnit3TestAdapter" Version="4.4.2" />
-    <PackageReference Include="Verify.NUnit" Version="20.1.0" />
+    <PackageReference Include="Verify.NUnit" Version="20.1.1" />
     <!-- end-snippet -->
   </ItemGroup>
 </Project>