Update Makefile to include macos specific target

[rw-bsi]

for the mac aficionados: added install-macos target (pulls in correct python package and uses correct unzip format)

install-macos: venv
	. $(VIRTUAL_ENV)/bin/activate && \
	pip install --upgrade pip && \
	pip install -r requirements.txt && \
	wget -O /tmp/ifcopenshell_python.zip "https://s3.amazonaws.com/ifcopenshell-builds/ifcopenshell-python-311-v0.7.9-c18e4ea-macos64.zip" && \
	mkdir -p $(VIRTUAL_ENV)/lib/python3.11/site-packages && \
	unzip /tmp/ifcopenshell_python.zip -d .dev/venv/lib/python3.11/site-packages && \
	rm /tmp/ifcopenshell_python.zip

[rw-bsi]

Low risk, will approve it myself