[pre-commit] Set verbose=false for check-whitespace

[pre-commit] Set verbose=false for check-whitespace

Currently, the pre-commit check check-whitespace has verbose=true:
...
$ pre-commit run --all-files check-whitespace
check-whitespace........................................................Passed
- hook id: check-whitespace
- duration: 0.3s
$
...

That's not necessary, since:
- check-whitespace has no output if the check passes, and
- pre-commit shows the output anyway if the check fails.

Fix this by removing the verbose setting, getting us instead:
...
$ pre-commit run --all-files check-whitespace
check-whitespace........................................................Passed
$
...

Approved-By: Simon Marchi <simon.marchi@efficios.com>