Bump ServiceStack from 4.0.19 to 5.9.2 in /src/RazorRockstars.MacHost

Bumps [ServiceStack](https://github.com/ServiceStack/ServiceStack) from 4.0.19 to 5.9.2.
- [Release notes](https://github.com/ServiceStack/ServiceStack/releases)
- [Commits](ServiceStack/ServiceStack@v4.0.19...v5.9.2)

Signed-off-by: dependabot[bot] <[email protected]>

Author: dependabot[bot]

src/RazorRockstars.MacHost/packages.config

@@ -1,6 +1,6 @@
 <?xml version="1.0" encoding="utf-8"?>
 <packages>
-  <package id="ServiceStack" version="4.0.19" targetFramework="net40" />
+  <package id="ServiceStack" version="5.9.2" targetFramework="net40" />
   <package id="ServiceStack.Client" version="4.0.19" targetFramework="net40" />
   <package id="ServiceStack.Common" version="4.0.19" targetFramework="net40" />
   <package id="ServiceStack.Interfaces" version="4.0.19" targetFramework="net40" />