Build a static TA-Lib C when none is installed; add opt-in TSAN build

[Tapanhaz]

Changes

1. Static TA-Lib C fallback (setup.py):
   • A system TA-Lib is used only if its reported version (TA_GetVersionString) is >= TALIB_C_VER.
   • Otherwise the release tarball is built with CMake as a static library and linked into talib._ta_lib.
2. sdist ships .pyx only: cythonization now happens inside build_ext, and include talib/*.c is removed from MANIFEST.in.
3. CI:
   • wheels, tests and test-dev no longer build TA-Lib C by hand.
   • Custom auditwheel/delocate repair commands are dropped.
   • test-dev.yml builds C dev through TALIB_C_URL.
4. TSAN (opt-in):
   • TA_TSAN=1 builds the extension and a static TA-Lib C with ThreadSanitizer.
   • make test-tsan runs the threading tests.
   • tsan.yml runs the suite on free-threaded 3.14t and 3.15t using prebuilt TSAN images.

[mrjbq7]

What's the point of this PR?

[mrjbq7]

There's a bunch of issue with this, not least of which is I want to ship the C files so that cython is not required to install this module...

[Tapanhaz]

Thanks for the feedback, I'll close this.

For the record, the point was: pip builds from source fails
unless TA-Lib C is already installed. This builds a pinned TA-Lib C statically
when no suitable system copy is available, so pip install works without a
manual TA-Lib C install.

On Cython: pip fetches it automatically through build-system.requires, so users
never install it by hand. I see the case you want to keep, installs without
Cython (--no-build-isolation, distro builds).

Happy to revisit a narrower version if there's interest.

[mrjbq7]

Sorry, I'm not against your PR, I just didn't understand it.

so the main motivation is install from the source code should be able to build against TA-Lib static C library , like the wheels do?

[Tapanhaz]

Yes. When installing from source, the build currently needs TA-Lib C installed first. With this
change it builds a pinned TA-Lib C as a static library and links it in when no
suitable system copy is found, so the result is self-contained, like the wheels.

Nothing changes if a suitable TA-Lib is already installed (version >= TALIB_C_VER)
or if TA_INCLUDE_PATH / TA_LIBRARY_PATH are set, so packagers aren't affected.

[mrjbq7]

I'm considering a version of this change. While I test it, are there platforms or architectures or versions of Python that we don't have support for that is motivating this change for you?