[TIMOB-26721] iOS: Cannot deploy app extensions due to hardcoded Swift settings

[This PR](https://github.com/appcelerator/titanium_mobile/pull/8944) currently breaks iOS extension deployment: We are using an Action Extension which is written in Swift. When deploying it, the build is rejected because of containing a Frameworks/ directory in the .appex bundle. Inside it, the Swift standard libraries are added (because of [this line](https://github.com/appcelerator/titanium_mobile/pull/8944/files#diff-f430483233aa01af5b10df8390f9635dR3502)), which is invalid if your main target already contains Swift - like in our case. The fix is to check if the main target already includes Swift and set the ALWAYS_EMBED_SWIFT_STANDARD_LIBRARIES flag of the extension to NO. We currently hardcoded the value to be unblocked, but eventually a quick PR setting and checking the hasSwiftFiles for the main target.