[3.12] gh-128504: Upgrade doctest to ubuntu-24.04 (GH-128506) (#128518)

gh-128504: Upgrade doctest to ubuntu-24.04 (GH-128506)
(cherry picked from commit 2228e92)

Co-authored-by: Damien <81557462+Damien-Chen@users.noreply.github.com>
Co-authored-by: blurb-it[bot] <43283697+blurb-it[bot]@users.noreply.github.com>
Co-authored-by: Hugo van Kemenade <1324225+hugovk@users.noreply.github.com>

.github/workflows/reusable-docs.yml

@@ -96,7 +96,7 @@ jobs:
   # Run "doctest" on HEAD as new syntax doesn't exist in the latest stable release
   doctest:
     name: 'Doctest'
-    runs-on: ubuntu-22.04
+    runs-on: ubuntu-24.04
     timeout-minutes: 60
     steps:
     - uses: actions/checkout@v4