`rez_pip_version` metadata missing from produced package.py files

[brycegbrazen]

When running rez-pip2 on any package, the rez_pip_version metadata is missing from the produced package.py file.

This metadata is shown to be present in the docs but does not appear in produced package.py files.

Environment

• Windows 10
• Rez version 2.112.0
• Rez python version 3.7
• rez-pip 0.3.1

To Reproduce

1. Install new rez-pip
2. rez-pip2 semver==3.0.2 (can also try requests==2.31.0 or any other package at all)

Expected Behavior rez_pip_version metadata present in pip attribute of package.py.

Actual Behavior rez_pip_version is missing from pip attribute of package.py

[brycegbrazen]

Looks like we need to add a tiny bit of new code here.

@JeanChristopheMorinPerso mentioned we could just get the current version with importlib_metadata.version('rez-pip')

[JeanChristopheMorinPerso]

This is fixed in the latest version.