Update my pod causes error in GoogleDataTransport Umbrella header

Adding onto Paul's answer: I also had to clear my Pod cache.

rm -rf ~/Library/Developer/Xcode/DerivedData/
rm -rf ~/Library/Caches/CocoaPods/
pod deintegrate
pod update

If you are using Flutter, you probably want to do the flutter clean too.

flutter clean

This works for me

# clear cached artifacts/dependencies
rm -rf ~/Library/Developer/Xcode/DerivedData/
rm -rf ~/Library/Caches/CocoaPods/
rm -rf clone/ios/Pods/
pod cache clean --all

# clear flutter - skip the next 3 lines if you're not using flutter
flutter clean
flutter pub get
cd ios

# run pod install
rm Podfile.lock
pod install --repo-update

rm -rf ~/Library/Developer/Xcode/DerivedData/
pod deintegrate
pod update

The GoogleDataTransport references are lingering from old pod versions