Change to use .local/lib/rustpython

Lib/site.py

@@ -335,7 +335,8 @@ def getsitepackages(prefixes=None):
 
         if os.sep == '/':
             sitepackages.append(os.path.join(prefix, "lib",
-                                        "python%d.%d" % sys.version_info[:2],
+                                        # XXX changed for RustPython
+                                        "rustpython%d.%d" % sys.version_info[:2],
                                         "site-packages"))
         else:
             sitepackages.append(prefix)