Update CI workflow to use Ubuntu 24.04 and Python 3.14 stable

Author: alex

.github/workflows/ci.yml

@@ -22,7 +22,7 @@ jobs:
         run: mypy --strict certifi
 
   test:
-    runs-on: ubuntu-22.04
+    runs-on: ubuntu-24.04
     strategy:
       matrix:
         python-version:
@@ -33,7 +33,7 @@ jobs:
         - "3.11"
         - "3.12"
         - "3.13"
-        - "3.14-dev"
+        - "3.14"
     steps:
     - uses: actions/checkout@8e8c483db84b4bee98b60c0593521ed34d9990e8 # v6.0.1
     - name: Set up Python ${{ matrix.python-version }}