BIM Preflight check test for IFCv4 support fails quietly on python >= 3.9

[mrevl]

In https://github.com/yorikvanhavre/BIM_Workbench/blob/master/BimPreflight.py
Context:
from packaging import version
cur_version = version.parse(ifcopenshell.version)
if type(cur_version) == version.LegacyVersion:

However as per python 3.9 LegacyVersion got removed, which then quietly causes
except Exception as e:
self.failed(test)

to get thrown.

Ideas:
-remove the check on LegacyVersion
-test for python <3.9

In this case it looks like a workaround for a problem that wasn't supposed to exist in the first place, haven't looked into this too deeply yet.

For more info see
pypa/packaging#530

[yorikvanhavre]

Hopefully fixed now! Thanks for reporting!