Migrate from cbcbox to mipster for the bundled CBC library

cbcbox shipped CBC source builds; mipster (https://pypi.org/project/mipster/)
ships self-contained, hardware-tuned wheels for Linux x86_64/aarch64,
macOS x86_64/arm64, and Windows x86_64 with CPUID auto-dispatch
(generic / AVX2 / Haswell / NEON variants).

- Replace `cbcbox>=2.929` with `mipster>=0.2.0`.
- Use `mipster.lib_path()` instead of platform-specific path joining;
  this returns the right shared library for the current OS and
  selected variant.
- Drop the manual libCbc.so / libCbc-0.dll / libCbc.dylib branching.
- Keep `os.add_dll_directory()` on Windows so the loader can find the
  sibling MinGW runtime DLLs that mipster bundles next to libmipster-N.dll.
- Remove unused Cbc_get/setAllowablePercentageGap CFFI declarations
  (these are not exported by libmipster and were never called).

Author: Haroldo G. Santos

mip/cbc.py

@@ -70,36 +70,20 @@
         cbclib = ffi.dlopen(libfile)
         os.chdir(old_dir)
     else:
-        import cbcbox as _cbcbox
-
-        _lib_dir = _cbcbox.cbc_lib_dir()
-        if "linux" in platform.lower():
-            if not os_is_64_bit:
-                raise NotImplementedError("Linux 32 bits platform not supported.")
-            libfile = os.path.join(_lib_dir, "libCbc.so")
-        elif platform.lower().startswith("win"):
-            if not os_is_64_bit:
-                raise NotImplementedError("Win32 platform not supported.")
-            # autotools/MinGW places DLLs under bin/, not lib/
-            _bin_dir = os.path.join(_cbcbox.cbc_dist_dir(), "bin")
-            libfile = os.path.join(_bin_dir, "libCbc-0.dll")
-            if not os.path.exists(libfile):
-                raise FileNotFoundError(
-                    "libCbc-0.dll not found in cbcbox Windows distribution at"
-                    " {}. The cbcbox Windows wheel may only contain a static"
-                    " libCbc.a. A shared libCbc-0.dll is required.".format(_bin_dir)
-                )
-            # Python 3.8+ ignores PATH for DLL resolution; use add_dll_directory
+        import mipster as _mipster
+
+        if not os_is_64_bit:
+            raise NotImplementedError("32-bit platforms are not supported.")
+        libfile = _mipster.lib_path()
+        if platform.lower().startswith("win"):
+            # Python 3.8+ ignores PATH for DLL resolution; let Windows find
+            # any sibling DLLs (libgcc, libstdc++, libwinpthread) via
+            # add_dll_directory on the directory holding libmipster-N.dll.
+            _bin_dir = os.path.dirname(libfile)
             if hasattr(os, "add_dll_directory"):
                 os.add_dll_directory(_bin_dir)
             elif _bin_dir not in os.environ.get("PATH", ""):
                 os.environ["PATH"] = _bin_dir + ";" + os.environ["PATH"]
-        elif platform.lower().startswith("darwin") or platform.lower().startswith(
-            "macos"
-        ):
-            libfile = os.path.join(_lib_dir, "libCbc.dylib")
-        else:
-            raise NotImplementedError("Your operating system/platform is not supported")
         cbclib = ffi.dlopen(libfile)
     has_cbc = True
 except Exception as e:
@@ -317,11 +301,6 @@
     void Cbc_setAllowableFractionGap(Cbc_Model *model,
         double allowedFracionGap);
 
-    double Cbc_getAllowablePercentageGap(Cbc_Model *model);
-
-    void Cbc_setAllowablePercentageGap(Cbc_Model *model,
-        double allowedPercentageGap);
-
     double Cbc_getMaximumSeconds(Cbc_Model *model);
 
     void Cbc_setMaximumSeconds(Cbc_Model *model, double maxSeconds);

pyproject.toml

@@ -34,7 +34,7 @@ classifiers = [
 ]
 dynamic = ["version"]
 
-dependencies = ["cffi>=1.15", "cbcbox>=2.929"]
+dependencies = ["cffi>=1.15", "mipster>=0.2.0"]
 
 [project.optional-dependencies]
 numpy = [