Bump ruff from 0.15.20 to 0.15.21 (#297)

---
updated-dependencies:
- dependency-name: ruff
  dependency-version: 0.15.21
  dependency-type: direct:development
  update-type: version-update:semver-patch
...

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Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

Author: dependabot[bot]

pyproject.toml

@@ -34,7 +34,7 @@ dev = [
     "pylint == 4.0.6",
     "pyrefly==1.1.1",
     "pytest == 9.1.1",
-    "ruff == 0.15.20"
+    "ruff == 0.15.21"
 ]
 
 [build-system]