Update tests-minimal to Alpine 3.20

Author: bernardotorres

.builds/tests-minimal.yml

@@ -3,7 +3,7 @@
 # TODO: It might make more sense to test with an older Ubuntu or Fedora version
 # here, and consider that our "oldest suppported environment".
 
-image: alpine/v3.19 # python 3.11
+image: alpine/3.20 # python 3.12
 packages:
   - docker
   - docker-cli
@@ -28,7 +28,7 @@ tasks:
   - setup: |
       cd vdirsyncer
       # Hack, no idea why it's needed
-      sudo ln -s /usr/include/python3.11/cpython/longintrepr.h /usr/include/python3.11/longintrepr.h
+      sudo ln -s /usr/include/python3.12/cpython/longintrepr.h /usr/include/python3.12/longintrepr.h
       make -e install-dev
   - test: |
       cd vdirsyncer