misc: WITH_PYTHON -> YOSYS_ENABLE_PYTHON

For consistency.

Also trying a new thing: only rebuilding objects that use the pybind11 library. The idea is these are the only objects that include the Python/pybind headers and thus the only ones that depend on the Python ABI in any capacity, so other objects can be reused across wheel builds. This has the potential to cut down build times.

pyosys/generator.py

@@ -349,7 +349,7 @@ class PyosysWrapperGenerator(object):
         cxx_std = os.getenv("CXX_STD", "c++17")
         return ParserOptions(
             preprocessor=make_gcc_preprocessor(
-                defines=["_YOSYS_", "WITH_PYTHON"],
+                defines=["_YOSYS_", "YOSYS_ENABLE_PYTHON"],
                 gcc_args=[preprocessor_bin, "-fsyntax-only", f"-std={cxx_std}"],
                 include_paths=[str(__yosys_root__), py_include, pybind11.get_include()],
             ),