change(pypi): use the python package version instead of sha in repo names

Initially the repo name generate was very conservative and we had sha256
as the endings of the repo names. With this change we have more human
readable repository names. In order to still comply with the bazel label
rules, we are normalizing the versions to only have `_` and `.`
characters.

This is an alternative fix to the error message seen in
bazel-contrib#1837 (comment)

Author: aignas

CHANGELOG.md

@@ -37,6 +37,8 @@ A brief description of the categories of changes:
   by default. Users wishing to keep this argument and to enforce more hermetic
   builds can do so by passing the argument in
   [`pip.parse#extra_pip_args`](https://rules-python.readthedocs.io/en/latest/api/rules_python/python/extensions/pip.html#pip.parse.extra_pip_args)
+* (pypi, bzlmod) Change the repo naming when `experimental_index_url` is enabled
+  to include the version number in the external repository names.
 
 {#v0-0-0-fixed}
 ### Fixed