qt6_tool: Fix flake8 warnings


Change-Id: I5f9e4a0acff683ebcdbd295e0c914039b3391ac6
Reviewed-by: Adrian Herrmann <adrian.herrmann@qt.io>
commitfb8c3f7be23743eb7a6298f9c48fd22cbc91f0b3
parente2839f90926befcb013f92f291dcf2f8dc327b54
authorFriedemann Kleint <Friedemann.Kleint@qt.io>
committerFriedemann Kleint <Friedemann.Kleint@qt.io>
commit timeWed, 3 Jul 2024 11:26:44 +0000