chore(deps): update dependency nsubstitute to 5.3.0 (#51)

Author: renovate[bot]

tests/Prometheus.Client.HttpClient.Tests/Prometheus.Client.HttpClient.Tests.csproj

@@ -8,7 +8,7 @@
     <PackageReference Include="Fennel" Version="0.3.0" />
     <PackageReference Include="FluentAssertions" Version="6.12.1" />
     <PackageReference Include="Microsoft.NET.Test.Sdk" Version="17.11.1" />
-    <PackageReference Include="NSubstitute" Version="5.1.0" />
+    <PackageReference Include="NSubstitute" Version="5.3.0" />
     <PackageReference Include="xunit" Version="2.9.2" />
     <PackageReference Include="xunit.runner.visualstudio" Version="2.8.2">
       <PrivateAssets>all</PrivateAssets>