Drop Python 3.12 support (#135589)

script/hassfest/mypy_config.py

@@ -9,8 +9,6 @@ import os
 from pathlib import Path
 from typing import Final
 
-from homeassistant.const import REQUIRED_PYTHON_VER
-
 from .model import Config, Integration
 
 # Component modules which should set no_implicit_reexport = true.
@@ -31,7 +29,18 @@ HEADER: Final = """
 """.lstrip()
 
 GENERAL_SETTINGS: Final[dict[str, str]] = {
-    "python_version": ".".join(str(x) for x in REQUIRED_PYTHON_VER[:2]),
+    # We use @dataclass_transform in all our EntityDescriptions, causing
+    # `__replace__` to be already synthesized by mypy, causing **every** use of
+    # our entity descriptions to fail:
+    #
+    # error: Signature of "__replace__" incompatible with supertype "EntityDescription"
+    #
+    # Until this is fixed in mypy, we keep mypy locked on to Python 3.12 as we
+    # have done for the past few releases.
+    #
+    # Ref: https://github.com/python/mypy/issues/18216
+    # "python_version": ".".join(str(x) for x in REQUIRED_PYTHON_VER[:2]),
+    "python_version": "3.12",
     "platform": "linux",
     "plugins": ", ".join(  # noqa: FLY002
         [