feat(testing): bump deps for Python > 3.8

New versions are not compatible with Python 3.8, so keep the old ones for this specfic version.

Author: StephenSorriaux

constraints.txt

@@ -1,8 +1,12 @@
 # Consistent testing environment.
 black==22.10.0
-coverage==6.3.2
+coverage==6.3.2; python_version=="3.8"
+coverage==7.10.7; python_version > "3.8"
 flake8==5.0.2
 objgraph==3.5.0
-pytest==6.2.5
-pytest-cov==3.0.0
-pytest-timeout==2.2.0
+pytest==6.2.5; python_version=="3.8"
+pytest==8.4.2; python_version > "3.8"
+pytest-cov==3.0.0; python_version=="3.8"
+pytest-cov==7.0.0; python_version > "3.8"
+pytest-timeout==2.2.0; python_version=="3.8"
+pytest-timeout==2.4.0; python_version > "3.8"