CI: a better type error information to find the key point

[Zeroto521]

Is your feature request related to a problem? Please describe.

If stubs.yml CI fails, it only shows "Baseline test files are out of date, run: ./stubs/baseline.sh on Python 3.14 to update". It's hard to find the problem.

PySCIPOpt/.github/workflows/stubs.yml

Lines 58 to 65 in 43fd8e3

	- name: Check baseline test files are up to date
	run: |
	./stubs/baseline.sh
	# we need to ignore the .deb file we download above
	if [[ -n $(git status --porcelain --untracked-files=no) ]]; then
	echo "Baseline test files are out of date, run: ./stubs/baseline.sh on Python ${{ env.PYTHON_VERSION }} to update"
	exit 1
	fi

Describe the solution you'd like

Add a git diff commnad for stubs.yml like

./stubs/baseline.sh
if [[ -n $(git status --porcelain --untracked-files=no) ]]; then
  echo "Baseline test files are out of date. Diff:"
  git --no-pager diff -- tests/@types/   # ← here, show the difference
  exit 1
fi