Improvements to integration tests
This MR makes the following improvements to the integration testing configuration
- set
*_NUM_THREADS=1
for all appropriate variables - to try and force all integration tests to only use a single core - run top-level pytest with better options
- enable
marks
for test commands, mainly to mark things asflaky
- add a
test/pytest
option to simplify running pytest suites as integration tests - use the
test/pytest
option everywhere a manualpytest
call was configured
This is an evolution of !386 (closed) with a better branch name.