Add Python 3.14 to CI (#562)

Author: bieniu

.github/workflows/test.yml

@@ -15,6 +15,7 @@ jobs:
         python-version:
           - "3.12"
           - "3.13"
+          - "3.14.0-beta.3"
 
     steps:
       - name: Check out repository

pyproject.toml

@@ -108,13 +108,14 @@ source = ["gios"]
 legacy_tox_ini = """
 
 [tox]
-envlist = py312, py313, lint, typing, coverage
+envlist = py312, py313, py314, lint, typing, coverage
 skip_missing_interpreters = True
 
 [gh-actions]
 python =
   3.12: py312, lint, typing, coverage
   3.13: py313
+  3.14: py314
 
 [testenv]
 commands =