[3.13] Pin the doctest workflow to Ubuntu 22.04 (GH-125236) (#125240)

Co-authored-by: Adam Turner <[email protected]>

Author: miss-islington

.github/workflows/build.yml

@@ -42,7 +42,7 @@ jobs:
 
   check_abi:
     name: 'Check if the ABI has changed'
-    runs-on: ubuntu-latest
+    runs-on: ubuntu-22.04
     needs: check_source
     if: needs.check_source.outputs.run_tests == 'true'
     steps:

.github/workflows/reusable-docs.yml

@@ -95,7 +95,7 @@ jobs:
   # Run "doctest" on HEAD as new syntax doesn't exist in the latest stable release
   doctest:
     name: 'Doctest'
-    runs-on: ubuntu-latest
+    runs-on: ubuntu-22.04
     timeout-minutes: 60
     steps:
     - uses: actions/checkout@v4