Uvenv

Updates

* upgrade to `uv` 0.4.20

Updates

* upgrade to `uv` 0.4.19

Feature

* `uvenv self link` to create a symlink to `~/.local/bin/uvenv` - which is useful when you installed `uvenv` in a
separate virtualenv.

Docs

* Described multiple ways of installing `uvenv` in Ubuntu 24.04 (for `externally-managed-environment` errors)

Fix

* improved error messages for `ensurepath`
* bump dependencies (uv to 0.4.10)

Fix

* rollback to pip-only self update (but keep new functions for documentation purposes)
* exclude yanked versions from 'latest' version

Fix

* rollback slightly: still use `pip freeze` as backup