gstreamer_python: hardcoded path for libgstpython.dylib
This issue affects Reachy Mini users (and likely others installing `gstreamer_python` on macOS).
#### **Environment:**
* macOS (Apple Silicon / x86_64)
* GStreamer 1.28.1
* Python 3.12 installed via Homebrew or `uv` (not python.org)
#### **Problem:**
Process that loads `libgstpython.dylib` crashes with:
`Library not loaded: /Library/Frameworks/Python.framework/Versions/3.12/Python`\
`Reason: tried: '/Library/Frameworks/Python.framework/Versions/3.12/Python' (no such file)`
#### **Identified Cause:**
The macOS fixup block in `_create_wheels()` (\[cerbero/packages/wheel/packager.py\](https://gitlab.freedesktop.org/gstreamer/cerbero/-/blob/1.28/cerbero/packages/wheel/packager.py)) adds `@rpath` entries via `install_name_tool` but does not replace the absolute `LC_LOAD_DYLIB` path to `Python.framework` baked into `libgstpython.dylib` at build time.
`OSXRelocator` is not called for `gstreamer_python` wheel contents.
issue