igwn-lalsuite-dev{el} is missing Python requirements

Problem summary

The igwn-lalsuite-dev{el} metapackage is missing many of the Python packages necessary to ./configure LALSuite properly.

This is now exposed by !131 (merged):

+ ./configure
...
=== configuring in lal (/builds/duncanmmacleod/metapackages/lalsuite/lal)
configure: running /bin/bash ./configure --disable-option-checking '--prefix=/builds/duncanmmacleod/metapackages/lalsuite/_inst'  --cache-file=/dev/null --srcdir=.
...
checking /usr/bin/python3 version... 3.7
checking for sysconfig... yes
checking for NumPy... configure: error: could not import NumPy
configure: error: ./configure failed for lal

To reproduce

Install igwn-lalsuite-dev{el} on an otherwise empty system and then run

WORKING_DIR=$(mktemp -d)
git clone https://git.ligo.org/lscsoft/lalsuite.git ${WORKING_DIR}
cd "${WORKING_DIR}"
./00boot
./configure

What should happen?

After installing only igwn-lalsuite-dev{el} at least the ./configure should work, ideally make && make install as well (but probably not make check, not sure).

System information