deps(dev): update gunicorn requirement in the major-dependencies group

Updates the requirements on [gunicorn](https://github.com/benoitc/gunicorn) to permit the latest version.

Updates `gunicorn` to 23.0.0
- [Release notes](https://github.com/benoitc/gunicorn/releases)
- [Commits](benoitc/gunicorn@21.0.0...23.0.0)

---
updated-dependencies:
- dependency-name: gunicorn
  dependency-type: direct:development
  dependency-group: major-dependencies
...

Signed-off-by: dependabot[bot] <[email protected]>

setup.py

@@ -44,7 +44,7 @@
     extras_require={
         "cloud-run": [
             "flask==3.*",
-            "gunicorn>=21,<23",
+            "gunicorn>=21,<24",
         ],
         "tests": [
             "pytest-cov>=4,<6",