fix: remove NSLocationWhenInUseUsageDescription from PERMISSION_LOCATION plistKeys

[deandreamatias]

Fix SwiftPM compiles requestAlwaysAuthorization for locationWhenInUse when only exist foreground location propouse (NSLocationWhenInUseUsageDescription plistKey)

Close #1558

Verify behavior

• Simple script to verify after compile an app

if strings build/ios/archive/Runner.xcarchive/Products/Applications/Runner.app/Runner \
    | grep -q requestAlwaysAuthorization; then
  echo "ERROR: requestAlwaysAuthorization found — App Store will reject (ITMS-90683)." >&2
  exit 1
fi

⚠️ Be careful, if you have more packages that interact with permissions, like geolocator or location, can get false positives for flutter-permission-handler too.

Pre-launch Checklist

• I made sure the project builds.
• I read the Contributor Guide and followed the process outlined there for submitting PRs.
• I updated pubspec.yaml with an appropriate new version according to the pub versioning philosophy, or this PR is does not need version changes.
• I updated CHANGELOG.md to add a description of the change.
• I updated/added relevant documentation (doc comments with ///).
• I rebased onto main.
• I added new tests to check the change I am making, or this PR does not need tests.
• I made sure all existing and new tests are passing.
• I ran dart format . and committed any changes.
• I ran flutter analyze and fixed any errors.