flow tests repeated runs to re-install include files.

[petersilva]

latest versions of sr3 don´t override existing files when converting, but consider it an error.
flow_tests need to remove include files installed at end of test, otherwise next test will not
overwrite them.

ractal% ./flow_setup.sh; ./flow_limit.sh
sr python version is: , version: 3.00.51rc1 
sr c is: /usr/bin/sr3_cpump, PFX= version: 3.23.12 
Cleaning previous flow test logs...
Adding flakey broker flow test configurations...
2023-12-18 14:25:43,836 260407 [ERROR] sarracenia.sr convert cpump/cpump/cno_trouble_f00.inc already exists in v3, remove /home/peter/.config/sr3/cpump/cno_trouble_f00.inc to convert again

2023-12-18 14:25:45,011 260414 [ERROR] sarracenia.sr convert shovel/shovel/no_trouble_f00.inc already exists in v3, remove /home/peter/.config/sr3/shovel/no_trouble_f00.inc to convert again

2023-12-18 14:25:46,176 260424 [INFO] root convert wrote conversion from v2 cpost/pelle_dd1_f04.conf to sr3

missing state for cpost/pelle_dd1_f04
2023-12-18 14:25:47,325 260427 [INFO] root convert wrote conversion from v2 cpost/pelle_dd2_f05.conf to sr3