[PR #1422/7a744a10 backport][stable-2.17] [WIP, needs vote before merging] collection_requirements.rst: update

[patchback[bot]]

This is a backport of PR #1422 as merged into devel (7a744a1094c4b1103d457d0f33765a2d2173ca92).

It's time to revise and update the requirements if needed. Forum topic.

Goals:

• Simplify it if possible (content, wording), make it easier to read
• Exclude irrelevant requirements (including those that don't work/very hard to control)
• Make maintainers and reviewers 's lives easier

Any suggestions are appreciated (in not touched parts as well)

Post tasks:

• [ ] Update https://github.com/ansible-collections/overview/blob/main/collection_checklist.md after merging this PR if needed.