scripts: Update to use exec_module() instead of load_module()

This is deprecated in python 3.12 and Fedora 35 is throwing warnings so
move to the new functions.

(From OE-Core rev: 655cd3f614d736416eab0d708b7c49674bf5c977)

Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

scripts/lib/scriptutils.py

@@ -18,7 +18,8 @@ import sys
 import tempfile
 import threading
 import importlib
-from importlib import machinery
+import importlib.machinery
+import importlib.util
 
 class KeepAliveStreamHandler(logging.StreamHandler):
     def __init__(self, keepalive=True, **kwargs):
@@ -82,7 +83,9 @@ def load_plugins(logger, plugins, pluginpath):
         logger.debug('Loading plugin %s' % name)
         spec = importlib.machinery.PathFinder.find_spec(name, path=[pluginpath] )
         if spec:
-            return spec.loader.load_module()
+            mod = importlib.util.module_from_spec(spec)
+            spec.loader.exec_module(mod)
+            return mod
 
     def plugin_name(filename):
         return os.path.splitext(os.path.basename(filename))[0]