fix typo of 'not' instead of 'now' for useInheritedMediaQuery

[timmaffett]

The doc comment for useInheritedMediaQuery has a typo of 'not' instead of 'now' and it is confusing at the @Deprecated() message clearly states it is now ignored.
(and indeed checking the code you can verify that it is indeed ignored)

existing code before PR:

/// {@template flutter.widgets.widgetsApp.useInheritedMediaQuery}
/// Deprecated. This setting is not ignored.
///                             ^^^
/// The widget never introduces its own [MediaQuery]; the [View] widget takes
/// care of that.
/// {@endtemplate}
@Deprecated(
  'This setting is now ignored. '
  'WidgetsApp never introduces its own MediaQuery; the View widget takes care of that. '
  'This feature was deprecated after v3.7.0-29.0.pre.'
)
final bool useInheritedMediaQuery;

Pre-launch Checklist

• [X ] I read the [Contributor Guide] and followed the process outlined there for submitting PRs.
• I read the [Tree Hygiene] wiki page, which explains my responsibilities.
• I read and followed the [Flutter Style Guide], including [Features we expect every widget to implement].
• I signed the [CLA].
• I listed at least one issue that this PR fixes in the description above.
• I updated/added relevant documentation (doc comments with ///).
• I added new tests to check the change I am making, or this PR is [test-exempt].
• All existing and new tests are passing.

[goderbauer]

Thank you for spotting and fixing this!

LGTM