Problem:
`vim.fs.dirname([[C:\User\XXX\AppData\Local]])` returns "." on
mingw/msys2.
Solution:
- Check for "mingw" when deciding `iswin`.
- Use `has("win32")` where possible, it works in "fast" contexts since
b02eeb6a72.
Fix the following two issues:
- pyenv root detection issue
When `PYENV_ROOT` environment variable is not set, neovim will detect
pyenv's root via `pyenv root` command, but which will be always fail
because `vim.fn.system()` returns result with additional `\n`. Using
`vim.system` instead prevents this problem. to trim it before check
whether it is exists
- python executable path detection issue
Filter unrelated `python-config` in cases where multiple python versions
are installed, e.g. `python-config`, `python3.10-config`,
`python3.11-config` etc.
This will help manage the overly granular checkhealth completion to go
from
```
vim.health
vim.lsp
vim.provider.clipboard
vim.provider.node
vim.provider.perl
vim.provider.python
vim.provider.ruby
vim.treesitter
```
to
```
vim.health
vim.lsp
vim.provider
vim.treesitter
```
