[OpenWrt 19.07] python-importlib-metadata: add new package

[ja-pa]

Maintainer: me
Compile tested: Turris Omnia (TOS4), OpenWrt master
Run tested: Turris Omnia (TOS4), OpenWrt 19.07

Description:
This PR is based on #8562 . It splits new packages to individuals PR.

Run tested:

>>> from importlib_metadata import version
>>> version('pip')
'19.2.3'

[jefferyto]

I think this package is only needed for the openwrt-19.07 branch, since master recently updated to Python 3.8. (This package backports a 3.8 module for older versions of Python.)

The install requirements for both pluggy and pytest list this package as necessary only for Python < 3.8.

[jefferyto]

And this may not be necessary for openwrt-19.07 later, if we update it to Python 3.8 before the branch is frozen.

[BKPepe]

@ja-pa ping

[neheb]

Commits should be squashed I think.

[BKPepe]

Yes, commits should be squashed to a single one and this PR should be changed just to openwrt-19.07 branch. Also, there is a new version.

[BKPepe]

Merging! Thanks for your contribution.

[jefferyto]

I thought since 19.07 has been released, only bug and security fixes would be merged into the openwrt-19.07 branch, not new packages?

[BKPepe]

This was stuck here for a while. This package is not going to be included in OpenWrt master (and OpenWrt 20.xx), because this package is part of Python 3.8. I don't know when 20.xx will be released and if it is decided then it is based on kernel 5.4, then it is going to be delayed.

Should be part of the next OpenWrt 19.xx release and unfortunately, I need to have this package in OpenWrt 19.07, because I updated jsonschema to its the latest version and it was not mention that it added importlib-metadata and it's a pity, but I didn't check setup.cfg for latest changes. :(

On the other hand, I don't need to have patch from this commit, which brings this package or have it included in feed.

[jefferyto]

I can't seem to find a package for jsonschema in the openwrt-19.07 branch?

[BKPepe]

Yep, that's correct. It is in Turris OS packages feed for now and I didn't find a time to push it here and it will help me also with Home Assistant, so I dont need to compile it manually each time. I should push those packages here, but hopefully I will do it next month. But jsonschema is part of Docker compose pull request.

[jefferyto]

And all those new packages will go into master, not openwrt-19.07. I still don't see why importlib-metadata needed to be in openwrt-19.07.

[BKPepe]

Just personal need. Nothing else.