CI: Fix print skipped tests
- [X] closes #30040
- [ ] tests added / passed
- [ ] passes `black pandas`
- [ ] passes `git diff upstream/master -u -- "*.py" | flake8 --diff`
- [ ] whatsnew entry

Looks like the format of the junit file that pytest generates has changed, and now tests are inside a `testsuite` tag, which makes the script to not find any tests. Instead of looking for them as immediate children of `testcase`, I look for them in all the tree (including subchildren).

CC: @jorisvandenbossche 