Fix lazy type resolution with relative imports
This fixes an issue where lazy types using relative imports (e.g., strawberry.lazy(".module")) would fail to resolve correctly when comparing with the __main__ module, potentially causing "Type X is defined multiple times in the schema" errors during test isolation.
This ensures that the fully resolved module name is used when comparing with __main__.__spec__.name, rather than the relative import path.
Releases contributed by @bellini666 via #4145