Stabilize PropertyLayer (#2440)

Removes the warning that the PropertyLayer is experimental, and thus stabilize it. It has been used in example models, integrated into the visualisation (both standalone and as part of the cell space) and in Mesa for almost a year without needing API changes.

Note that while the PropertyLayer itself is stable, not all it's integration might be, like the integration into the still experimental cell space.

Author: EwoutH

mesa/space.py

@@ -607,8 +607,6 @@ class PropertyLayer:
 
     """
 
-    propertylayer_experimental_warning_given = False
-
     def __init__(
         self, name: str, width: int, height: int, default_value, dtype=np.float64
     ):
@@ -653,15 +651,6 @@ def __init__(
 
         self.data = np.full((width, height), default_value, dtype=dtype)
 
-        if not self.__class__.propertylayer_experimental_warning_given:
-            warnings.warn(
-                "The new PropertyLayer and _PropertyGrid classes experimental. It may be changed or removed in any and all future releases, including patch releases.\n"
-                "We would love to hear what you think about this new feature. If you have any thoughts, share them with us here: https://github.com/projectmesa/mesa/discussions/1932",
-                FutureWarning,
-                stacklevel=2,
-            )
-            self.__class__.propertylayer_experimental_warning_given = True
-
     def set_cell(self, position: Coordinate, value):
         """Update a single cell's value in-place."""
         self.data[position] = value