Warn on Python 3.10 that 0.15 will not support it (#128)

Co-authored-by: OCCAM Coder <coder@occam.com.ua>

Author: ml31415

numpy_groupies/__init__.py

@@ -1,5 +1,7 @@
 from __future__ import annotations
 
+import sys
+import warnings
 from typing import TYPE_CHECKING, Any
 
 from numpy_groupies.aggregate_purepy import aggregate as aggregate_py
@@ -90,3 +92,11 @@ def uaggregate(
     else:
         __version__ = get_version(root="..", relative_to=__file__)
         del get_version
+
+if sys.version_info[:2] < (3, 11):
+    warnings.warn(
+        "numpy-groupies will require Python 3.11 or newer from version 0.15, "
+        "and the 0.14 releases are the last to support Python 3.10.",
+        DeprecationWarning,
+        stacklevel=2,
+    )

pyproject.toml

@@ -32,7 +32,7 @@ classifiers = [
     "Topic :: Software Development :: Libraries",
 ]
 keywords = ["accumarray", "aggregate", "groupby", "grouping", "indexing"]
-requires-python = ">=3.10"
+requires-python = ">=3.10" # 0.15 will raise this to ">=3.11"
 dependencies = ["numpy"]
 
 [project.optional-dependencies]