Fix pyinfo for Python 3.12 changes (#15103)

Author: hauntsaninja

mypy/pyinfo.py

@@ -7,10 +7,7 @@
 library found in Python 3.7. This file is run each mypy run, so it should be kept as fast as
 possible.
 """
-import os
-import site
 import sys
-import sysconfig
 
 if __name__ == "__main__":
     # HACK: We don't want to pick up mypy.types as the top-level types
@@ -22,6 +19,10 @@
 
     sys.path = old_sys_path
 
+import os
+import site
+import sysconfig
+
 
 def getsitepackages() -> list[str]:
     res = []
@@ -31,9 +32,7 @@ def getsitepackages() -> list[str]:
         if hasattr(site, "getusersitepackages") and site.ENABLE_USER_SITE:
             res.insert(0, site.getusersitepackages())
     else:
-        from distutils.sysconfig import get_python_lib
-
-        res = [get_python_lib()]
+        res = [sysconfig.get_paths()["purelib"]]
     return res