fix: remove enable-cgal

From ./configure --help:

```
  --enable-cgal           enables link with the CGAL library default=no
  --enable-cgal-header-only   enable build with header-only install of CGAL, e.g. as for CGALv5; in that case do not use --enable-cgal default=no
```

setup.py

@@ -116,7 +116,6 @@ def build_extensions(self):
                 "--disable-auto-ptr",
                 "--enable-allcxxplugins",
                 "--enable-cgal-header-only",
-                "--enable-cgal",
                 f"--with-cgaldir={cgal_dir}",
                 "--enable-swig",
                 "--enable-pyext",