Update english incorrect grammar for handlings-taps.md (#12128)

_Description of what this PR is changing or adding, and why:_

* update incorrect english grammar in handlings-taps.md file

_Issues fixed by this PR (if any):_

_PRs or commits this PR depends on (if any):_

## Presubmit checklist

- [X] This PR is marked as draft with an explanation if not meant to
land until a future stable release.
- [X] This PR doesn’t contain automatically generated corrections
(Grammarly or similar).
- [X] This PR follows the [Google Developer Documentation Style
Guidelines](https://developers.google.com/style) — for example, it
doesn’t use _i.e._ or _e.g._, and it avoids _I_ and _we_ (first person).
- [X] This PR uses [semantic line
breaks](https://github.com/dart-lang/site-shared/blob/main/doc/writing-for-dart-and-flutter-websites.md#semantic-line-breaks)
of 80 characters or fewer.

Author: emilakerman

src/content/cookbook/gestures/handling-taps.md

@@ -24,7 +24,7 @@ This recipe shows how to make a custom button that shows
 a snackbar when tapped with the following steps:
 
   1. Create the button.
-  2. Wrap it in a `GestureDetector` that an `onTap()` callback.
+  2. Wrap it in a `GestureDetector` and provide an `onTap()` callback.
 
 <?code-excerpt "lib/main.dart (GestureDetector)" replace="/return //g;/^\);$/)/g"?>
 ```dart