Add debug symbols for iOS and macOS builds

[mugikhan]

There is now an error message in Xcode 16 for a missing dSYM folder and DWARF file.

The archive did not include a dSYM for the powersync-sqlite-core.framework with the 
UUIDs [7E9FE23E-F16F-35CB-830B-54AD4C79F057]. Ensure that the archive's dSYM 
folder includes a DWARF file for powersync-sqlite-core.framework with the expected UUIDs.

[stevensJourney]

I tested this locally.

Initially I could reproduce the warning by using our latest powersync-sqlite-core pod and submitting an app build to TestFlight. The submission stated the above warning.

I then built the XCFramework locally from this repo, removed the powersync-sqlite-core pod dependency and linked the local XCFramework instead to my project. The submission to TestFlight succeeded without any warnings.

I'm happy to merge this from my side.

[rkistner]

There is already a v0.3.8 - need to merge main and bump again

[stevensJourney]

There is already a v0.3.8 - need to merge main and bump again

👍 Bumped again.