This PR applies IWYU fixes for `base/sequence_checker.h`.
The script dataset for this is:
```
HEADER_FUNCTION_SETS = [
(
'"base/sequence_checker.h"',
(
"SEQUENCE_CHECKER",
"DETACH_FROM_SEQUENCE",
"SequenceCheckerDoNothing",
"SequenceChecker",
"ScopedValidateSequenceChecker",
),
),
]
```
Bug: https://github.com/brave/brave-browser/issues/42212