PEP 101: Remove outdated info and add new info

A Tex installation is no longer needed, the docs are built on CI: https://github.com/python/release-tools/actions/workflows/source-and-docs-release.yml
Remove old note about asking Ewa for website access
Note new RMs should be added to PSRT
Add me to list of RMs
The make testall command is now make buildbottest: https://github.com/python/cpython/pull/110122
Replace MLs with Discord/Discourse

python / peps