CI: try pinning back pytest-rerunfailures instead

Author: tacaswell

requirements/testing/all.txt

@@ -2,11 +2,11 @@
 
 black<24
 certifi
-coverage!=6.3,!=7.10.6
+coverage!=6.3
 psutil
 pytest!=4.6.0,!=5.4.0,!=8.1.0
 pytest-cov
-pytest-rerunfailures
+pytest-rerunfailures!=16.0
 pytest-timeout
 pytest-xdist
 pytest-xvfb