docs: Remove egg fragments from pip install syntax from VCS

[matthewfeickert]

I cannot find the exact place I saw it earlier, but one example is pypa/pip#6598 (comment).

Oh, I see that

$ python -m pip install --upgrade "git+https://github.com/scikit-hep/pyhf.git#egg=pyhf[all]"

prints out

DEPRECATION: git+https://github.com/scikit-hep/pyhf.git#egg=pyhf[all] contains an egg fragment with a non-PEP 508 name pip 25.0 will enforce this behaviour change. A possible replacement is to use the req @ url syntax, and remove the egg fragment. Discussion can be found at pypa/pip#11617

@alexander-held oh you're on a M1 mac though, right? So inside your container is running under the linux/arm64 platform and so uname -m shows aarch64.

$ docker run --rm -ti --platform linux/arm64 python:3.9 /bin/bash
root@eab9f65bbf86:/# uname -m
aarch64

I have no idea what the support for all the packages that we depend on is for ARM64 macs at the moment. This might need to get added to the docs as a warning. :/

The following does work on an x86_64 machine:

python -m pip install --upgrade 'pyhf[all]@git+https://github.com/scikit-hep/pyhf.git'

and this new syntax should get added to the docs.

Originally posted by @matthewfeickert in #2111 (comment)