Remove unused import warning when installing via Cocoapods

[glm4]

Cocoapods installs the subspecs and makes the parent available already. This is not true for SPM, that needs to explicitly import other target dependencies when linking specific package products.

SPM issue:
When adding only RSSwiftNetworkingAlamofire as dependency to your application target, the files
APIClient+Alamofire.swift and AlamofireNetworkProvider.swift needs to import the core target(RSSwiftNetworking) to properly compile.

Implications when installing via Cocoapods:
The pod spec linting/pushing to trunk will fail (when not using --allow-warnings) due to the import RSSwiftNetworking statements in these files.