Avoid using deprecated ast attributes

This commit updates the logic in the expander to avoid using deprecated
attributes (like Num and Str) where possible. Additionally it
prioritizes using the newer version (Constant) to avoid deprecation
warnings.

Author: douglasjacobsen

lib/ramble/ramble/expander.py

@@ -839,16 +839,16 @@ def eval_math(self, node):
         others will generate integers (if the inputs are integers).
         """
         try:
-            if isinstance(node, ast.Num):
-                return self._ast_num(node)
-            elif isinstance(node, ast.Constant):
+            if hasattr(ast, "Constant") and isinstance(node, ast.Constant):
                 return self._ast_constant(node)
+            elif hasattr(ast, "Num") and isinstance(node, ast.Num):  # Deprecated, removed in 3.14
+                return self._ast_num(node)
             elif isinstance(node, ast.Name):
                 return self._ast_name(node)
             # TODO: Remove when we drop support for 3.6
             # DEPRECATED: Remove due to python 3.8
             # See: https://docs.python.org/3/library/ast.html#node-classes
-            elif isinstance(node, ast.Str):
+            elif hasattr(ast, "Str") and isinstance(node, ast.Str):  # Deprecated, removed in 3.14
                 return node.s
             elif isinstance(node, ast.Attribute):
                 return self._ast_attr(node)