Bump dart_style to de7e7260b81a4d4e2475c37faf0e89b83454dfdb

Changes:
```
> git log --format="%C(auto) %h %s" ca019b0..de7e726
 https://dart.googlesource.com/dart_style.git/+/de7e726 Clean up use of pkg:args, bump args dep (1784)
 https://dart.googlesource.com/dart_style.git/+/ade6076 Latest analyzer, prepare release (1783)
 https://dart.googlesource.com/dart_style.git/+/ec0048b Fix stray backtick in markdown documentation (1761)
 https://dart.googlesource.com/dart_style.git/+/34742d7 Bump actions/checkout from 4.2.2 to 5.0.0 in the github-actions group (1767)

```

Diff: https://dart.googlesource.com/dart_style.git/+/ca019b0498692ad78f5f0f0f6208a1258e17fc90..de7e7260b81a4d4e2475c37faf0e89b83454dfdb/
Change-Id: Iee68259581235a82630da6c16c8f1a0214887bde
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/461222
Auto-Submit: Kevin Moore <kevmoo@google.com>
Commit-Queue: Bob Nystrom <rnystrom@google.com>
Reviewed-by: Bob Nystrom <rnystrom@google.com>

Author: kevmoo

DEPS

@@ -126,7 +126,7 @@ vars = {
   #   and land the review.
   #
   # For more details, see https://github.com/dart-lang/sdk/issues/30164.
-  "dart_style_rev": "ca019b0498692ad78f5f0f0f6208a1258e17fc90", # rolled manually
+  "dart_style_rev": "de7e7260b81a4d4e2475c37faf0e89b83454dfdb", # rolled manually
 
   ### /third_party/pkg dependencies
   # 'tools/rev_sdk_deps.dart' will rev pkg dependencies to their latest; put an