Bump System.Collections.Immutable from 1.7.1 to 5.0.0 (#195)

Author: dependabot-preview[bot]

src/Hyperion.Tests/Hyperion.Tests.csproj

@@ -12,7 +12,7 @@
   <ItemGroup>
     <PackageReference Include="FluentAssertions" Version="5.10.3" />
     <PackageReference Include="Microsoft.NET.Test.Sdk" Version="$(TestSdkVersion)" />
-    <PackageReference Include="System.Collections.Immutable" Version="1.7.1" />
+    <PackageReference Include="System.Collections.Immutable" Version="5.0.0" />
     <PackageReference Include="xunit" Version="$(XunitVersion)" />
     <PackageReference Include="xunit.runner.visualstudio" Version="$(XunitRunnerVersion)" />
   </ItemGroup>