fix: adjust Python version requirement for slowapi compatibility

PYTHON VERSION FIX: Make project compatible with slowapi

Issue:
- Project requires Python >=3.14 but slowapi only supports Python <4.0
- Poetry dependency resolution failing due to Python version conflict
- slowapi versions 0.1.0-0.1.9 all require Python >=3.6,<4.0

Solution:
- Change requires-python from '>=3.13.5' to '>=3.13.5,<4.0'
- This makes the project compatible with slowapi Python requirements
- Maintains minimum Python version while adding upper bound

Expected results:
- Poetry dependency resolution should succeed
- slowapi should install properly
- All dependencies should be compatible
- Test workflow should proceed to execution

This resolves the Python version compatibility issue that was
blocking dependency installation.

pyproject.toml

@@ -110,7 +110,7 @@ authors = [
 ]
 readme = "cli/README.md"
 license = "MIT"
-requires-python = ">=3.13.5"
+requires-python = ">=3.13.5,<4.0"
 dependencies = [
     "click==8.3.1",
     "httpx==0.28.1",