Revert changes from main commits that were merged into blender-v4.1-release

The last good commit was f57e4c5b98.

After this one more fix was committed, this one is preserved as well:
67bd678887.

scripts/templates_py/custom_nodes.py

@@ -99,7 +99,7 @@ class MyCustomNode(MyCustomTreeNode, Node):
     def init(self, context):
         self.inputs.new('CustomSocketType', "Hello")
         self.inputs.new('NodeSocketFloat', "World")
-        self.inputs.new('NodeSocketVector', "!", use_multi_input=True)
+        self.inputs.new('NodeSocketVector', "!")
 
         self.outputs.new('NodeSocketColor', "How")
         self.outputs.new('NodeSocketColor', "are")