lalapps -> lal executable wrappers not working in nightly wheels

@karl-wette @adam-mercer @duncanmmacleod @leo-singer this was caught by the PyFstat pipelines: the backwards compatibility wrapper for lalapps_tconvert -> lal_tconvert from !1901 (merged), while working fine when building from current master, does not work when using the nightly dev wheels on PyPI. Same for the other tools moved in that MR.

python -m venv lalsuite-dev
source lalsuite-dev/bin/activate
pip install --upgrade pip setuptools  
pip install --pre lalsuite

lal_tconvert
Tue Mar 12 20:26:27 GMT 2002

lalapps_tconvert 700000000

WARNING: 'lalapps_tconvert' has been renamed to 'lal_tconvert'
WARNING: please update your scripts

/home/dkeitel/lalsuite-dev/lib/python3.9/site-packages/lalapps/bin/lalapps_tconvert: 7: exec: /builds/lscsoft/lalsuite/wheel/build/inst/bin/lal_tconvert: not found

The internal path must get set wrong. For reference, the working new executable is

which lal_tconvert 
/home/dkeitel/lalsuite-dev/bin/lal_tconvert

and not that werid /builds path it's trying to use.