provides a reliable way for Pyenv code to locate other parts of Pyenv code that are not under `PYENV_ROOT`

* tests: Work with Git entirely in a test repo

Co-authored-by: Ivan Pozdeev <vano@mail.mipt.ru>

Use tclConfig.sh/tkConfig.sh for future-proofing
3.14.0 doesn't detect Tcl/Tk with external libtommath, have to do it ourselves

Tcl/Tk 9.0 support was added in 3.13.0b3 and is not official as of 3.14.0;
the build with Homebrew version fails as of this writing

Fixes warnings "configure: WARNING: unrecognized options: --with-tcltk-libs, --with-tcltk-includes"

fix script

use global setup with bats with possibility to add specific test file _setup
use readlink in helper if realpath is not working as expected

fix bats warnings

Make sur that PYENV_TEST_DIR is created if mktemp failed
mock python3 usage by updating create_executable function
fix test by adding the right PATH
update path in plugin test
replace for loop with while read
don't use symlink for stub

Did not implement customizable priority due to unclear use feedback and more compilation in the code, can decide and do that separately

Tcl/Tk from MacPorts support is omitted due to CPython's only being compatible with 
Tcl/Tk 9 since 3.12.5 and 3.13.0.

Co-authored-by: Ivan Pozdeev <vano@mail.mipt.ru>

Mainly for tests, to avoid having to adjust call counts for stubs when the logic changes

add test to test all the flag types

Easy syncing with Rbenv is not as important now

More tailored for the emergent internal use cases

XCode Command Line Tools 15.0 was recently released, and it contains a
broken version of ncurses 6.0. Some uses of Python's `curses` module
will segfault when compiled with it. The solution is to switch to using
the version of ncurses from Homebrew, which is currently 6.4. Support
for ncurses 6 was added to Python 3.7 and was backported to 3.6 and 2.7,
so this change should not break any recently supported Python versions.

Tested with Python 3.12, 3.11, and 2.7, and all tests in
the `test.test_curses` module pass without issue.

See https://github.com/python/cpython/issues/109617 and
https://github.com/python/cpython/issues/69906 for more information.

The -s flag assures that nothing can be installed to user site-packages
but doesn't keep ensurepip from looking there for Pip.
If Pip is installed in the user site-packages directory, pip won't be installed
for the newly built python -- and its shim won't be created.
-I makes the build install Pip in any case.
The user site-packages installation will override it --
but we'll have the shim at least.

Guthub have recently preinstalled x64 Homebrew OpenSSL to stock MacOS runners. This has caused FreeBSD OpenSSL detection logic to erroneously trigger when running FreeBSD tests in MacOS because their paths happened to coincide.

Replaced checking a specific path with checking with pkg.

* Cleanup mocks logic
* Add test for `:latest`

Without rpath, python would link up to the system's libpython

Surprisingly, CPython doesn't search these with pkg-config
This is fixed upstream in 3.12.0a1

Likely in Ubuntu where it's only available as a snap

It was moved to `pyenv-install`

CPython 3.11+ dropped support for --with-tcl-tk-*
in favor of pure pkgconfig

Since 3.12, CPython can provide debug symbols in
Apple's nonstandard way, "dSYM bundles"

Support frozen builtin modules e.g. upip

Co-authored-by: Ivan Pozdeev <vano@mail.mipt.ru>

In Linux, it's not the primary source of packages and
cannot be used without build flag adjustments
thus has caused build failures.

`which` has been deprecated in Debian's debianutils 5.0+
They suggest using `type` and `command` as replacements:
3a8dd10b45 ,
610a65c6ef

This is needed to find other Python deps (e.g. libintl) in Homebrew if it has
nonstandard prefix (e.g. in Apple M1)

* Re-allow to search Homebrew for zlib everywhere

Don't override a user-supplied value

Link to the active version like other Homebrew deps --
this won't break when another binary-compatible version is installed.
Use a discovery method that doesn't break when other versions are present alongside.