ci: Use rerunfailures to retry the flaky vertexing test

This test is unfortunately flaky and produces differing output
sometimes. Until we can fix the underlying issue, retry the job.

Example of failure: https://github.com/acts-project/acts/runs/7296836937?check_suite_focus=true
Issue: #1091

Examples/Python/tests/requirements.in

@@ -2,3 +2,4 @@ pytest
 pytest-check
 uproot
 awkward
+pytest-rerunfailures

Examples/Python/tests/requirements.txt

@@ -26,8 +26,11 @@ pytest==7.0.1
     # via
     #   -r requirements.in
     #   pytest-check
+    #   pytest-rerunfailures
 pytest-check==1.0.4
     # via -r requirements.in
+pytest-rerunfailures==10.2
+    # via -r requirements.in
 tomli==2.0.1
     # via pytest
 uproot==4.1.9

Examples/Python/tests/test_examples.py

@@ -935,6 +935,7 @@ def test_vertex_fitting(tmp_path):
     ],
 )
 @pytest.mark.filterwarnings("ignore::UserWarning")
+@pytest.mark.flaky(reruns=2)
 def test_vertex_fitting_reading(
     tmp_path, ptcl_gun, rng, finder, inputTracks, entries, assert_root_hash
 ):