Preserve the real cause when the ifcopenshell wrapper fails to load (#8785)

* Keep real cause in wrapper ImportError

When the compiled wrapper exists for the current interpreter but fails
to load (for example a glibc version mismatch, as on AWS Lambda in
issue 5927), the bare except rewrote the error into the misleading
"IfcOpenShell not built for '<platform>'" message. Environments such
as AWS Lambda or the Blender add-on dialog only surface the final
exception message, so the actual cause was invisible and undiagnosable.

Keep the "not built for" message only when no matching binary is
present, and otherwise include the original loader error, chaining the
cause in both branches.

This change was AI-generated.

Fixes #5927

* Simplify wrapper import failure to a single message

Per review feedback, drop the filesystem scan and the two message
variants. Always raise the classic "IfcOpenShell not built for
'<platform>'" message with the original exception appended in
parentheses, still chained as the cause. Environments that only show
the final exception message (AWS Lambda, the Blender add-on dialog)
now surface the real loader error, such as the glibc version mismatch
in issue 5927, without any extra logic.

This change was AI-generated.

src/ifcopenshell-python/ifcopenshell/__init__.py

@@ -85,8 +85,8 @@ sys.path.append(os.path.abspath(os.path.join(os.path.dirname(__file__), "lib", p
 
 try:
     from . import ifcopenshell_wrapper
-except Exception:
-    raise ImportError("IfcOpenShell not built for '%s'" % python_distribution)
+except Exception as e:
+    raise ImportError("IfcOpenShell not built for '%s' (%s)" % (python_distribution, e)) from e
 
 # `_file`, `_stream` is used only for annotations inside this file,
 # see https://github.com/microsoft/pyright/discussions/9065.