Co-authored-by: binbjz <[email protected]>

* perf: replace a series of if statements with a case block. Add error
handling for case where unknown option is provided.
Same setup as rbenv-init for reading arguments.

* perf, docs: Recommend users to specify the shell for `pyenv init -`
Speeds up the startup by about 40% (in local testing, from ~50ms to ~30ms).
Reflect this in `pyenv init` hint text.

* style: remove unnecessary `root` variable in pyenv-init
* style: remove unnecessary variable declarations at the top of file in pyenv-init.

* perf: replace `cat <<` calls with `echo`
The builtin `echo` is about 100x faster. In tests, saves about 2-3ms.

* docs: document the `pyenv init - <shell>` performance boost in the Advanced Configuration section.

* style: test_helper.bash: avoid unnecessary ".." in produced PATH

* docs: fix a false statement about completions location in the Advanced Configuration section.

* future-proof PyVersion
* fix handling "-latest"
* Update default versions
* change -v argument to bool

* report more progress
* don't download SHA files for unsupported architectures

… for CPython (#3141)

Only CPython scripts use bundled dependencies for MacOS and two alternative tarballs

…, 24.7.1-1, 24.7.1-2, 24.9.0-0, 24.9.2-0, 24.11.0-0, 24.11.0-1 (#3142)

… from generation [no ci] (#3143)