1. Remove `dev_target` from suggested Firebase Test Lab iOS script and use wildcard instead.
2. First run `flutter clean` before building to avoid collisions between runs.
3. Use `zip --must-match` in case the xctestrun or `Release-iphoneos` directories are missing (like ran with `--profile` instead of `--release` on purpose) to fail instead of zipping up only part of what's needed.

This came out of a discussion with FTL about these instructions and I tried to run them locally and avoided setting `dev_target`.

See also #74428