[Bug]: Python integration test resolution model

Description

When running integration tests of a python-only repository, if it is installed in edit mode, the tests path is not correctly resolved. It is requested that these tests are executable with python installed in edit mode.

Steps to reproduce

source /cvmfs/dunedaq.opensciencegrid.org/setup_dunedaq.sh
setup_dbt latest
today_date=$(date +%y%m%d)
dbt-create -n last_fddaq $today_date
cd $today_date

. env.sh
dbt-build
dbt-workarea-env

cd pythoncode
git clone git@github.com:DUNE-DAQ/drunc.git
cd drunc

pip install .
dunedaq_integtest_bundle.sh -r drunc

pip install -e .
dunedaq_integtest_bundle.sh -r drunc

With the first attempt of the run, the integration tests should run normally, but with the second attempt, you should see

*** No integtests were found in the "drunc" repo(s) [with "" repos excluded].

Version and environment

NFD_DEV_260915_A9

Impact

Large

Anything else?

No response

Start with the dundaq_integtest_bundle.sh entry point and reproduce the difference between pip install . and pip install -e . in the provided commands. Trace how the drunc repository's integration-test path is resolved; done means the editable install discovers and runs the same integration tests as the regular install.