Update gunicorn requirement from ~=25.1.0 to ~=25.3.0

Updates the requirements on [gunicorn](https://github.com/benoitc/gunicorn) to permit the latest version.
- [Release notes](https://github.com/benoitc/gunicorn/releases)
- [Commits](benoitc/gunicorn@25.1.0...25.3.0)

---
updated-dependencies:
- dependency-name: gunicorn
  dependency-version: 25.3.0
  dependency-type: direct:production
...

Signed-off-by: dependabot[bot] <support@github.com>

Author: dependabot[bot]

requirements.txt

@@ -1,7 +1,7 @@
 requests~=2.32.5
 folium~=0.20.0
 Flask~=3.1.2
-gunicorn~=25.1.0
+gunicorn~=25.3.0
 IPy~=1.1
 translate~=3.8.0
 packaging~=26.0