build(deps): update flask requirement from ~=2.1 to ~=3.0

Updates the requirements on [flask](https://github.com/pallets/flask) to permit the latest version.
- [Release notes](https://github.com/pallets/flask/releases)
- [Changelog](https://github.com/pallets/flask/blob/main/CHANGES.rst)
- [Commits](pallets/flask@2.1.0...3.0.0)

---
updated-dependencies:
- dependency-name: flask
  dependency-type: direct:production
...

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

requirements.txt

@@ -1,3 +1,3 @@
-Flask~=2.1
+Flask~=3.0
 recipe-scrapers~=14.49
 gunicorn~=20.1.0