ci: run linters and tests on 24.04

This bumps the default Python version on CI to 3.12, which corresponds to the
version of the snap itself.

.github/workflows/tests.yaml

@@ -8,7 +8,7 @@ on:
 
 jobs:
   linters:
-    runs-on: ubuntu-22.04
+    runs-on: ubuntu-24.04
     steps:
       - name: Checkout code
         uses: actions/checkout@v4
@@ -23,11 +23,7 @@ jobs:
           sudo snap install --no-wait --classic node
           sudo snap install --no-wait --classic pyright
           sudo apt update
-          sudo apt install -y libapt-pkg-dev aspell aspell-en
-      - name: Set up Python 3.10
-        uses: actions/setup-python@v5
-        with:
-          python-version: "3.10"
+          sudo apt install -y python3 python3-dev libapt-pkg-dev aspell aspell-en
       - name: Install python packages and dependencies
         run: |
           pip install -U wheel -r requirements-jammy.txt -r requirements.txt -r requirements-dev.txt
@@ -62,7 +58,7 @@ jobs:
           make test-docs
 
   tests:
-    runs-on: ubuntu-22.04
+    runs-on: ubuntu-24.04
     steps:
       - name: Checkout code
         uses: actions/checkout@v4