Mouad Debbar 7b3b362623 [web] Cleaner output on LUCI (flutter/engine#41989)
Using ansi colors in LUCI results in output that looks like:
```
00:00 +0: loading flutter_tester_emulation_golden_test.dart                                                                                                                                            
00:01 +0: loading flutter_tester_emulation_golden_test.dart                                                                                                                                            
00:02 +0: loading flutter_tester_emulation_golden_test.dart
```

This PR disables colors on LUCI so that we get clean output that's easily scannable and searchable.
2023-05-12 21:50:22 +00:00
..