pyproject: Add minimum required Python version

cartridges/application.py

@@ -37,12 +37,10 @@ class Application(Adw.Application):
         """Import games from `sources`, skipping ones in `skip_ids`."""
         for source in sources:
             try:
-                new = source.get_games(skip_ids=skip_ids)
+                yield from source.get_games(skip_ids=skip_ids)
             except FileNotFoundError:
                 continue
 
-            yield from new
-
     @override
     def do_startup(self):
         Adw.Application.do_startup(self)

pyproject.toml

@@ -1,3 +1,6 @@
+[project]
+requires-python = ">= 3.13"
+
 [tool.pyright]
 exclude = ["**/__pycache__", "**/.*", "_build/**"]
 typeCheckingMode = "strict"