Bump CPython to 3.14.0rc1 (#710)

Author: geofft

cpython-unix/extension-modules.yml

@@ -206,6 +206,9 @@ _curses_panel:
 _datetime:
   sources:
     - _datetimemodule.c
+  setup-enabled-conditional:
+    - enabled: true
+      minimum-python-version: "3.14"
 
 _dbm:
   sources:

pythonbuild/downloads.py

@@ -82,10 +82,10 @@
         "python_tag": "cp313",
     },
     "cpython-3.14": {
-        "url": "https://www.python.org/ftp/python/3.14.0/Python-3.14.0b4.tar.xz",
-        "size": 23641472,
-        "sha256": "15e123e056abebba6de5e73cfa304459a8c82cafa85d4fc7fc6de80e6a3e1b39",
-        "version": "3.14.0b4",
+        "url": "https://www.python.org/ftp/python/3.14.0/Python-3.14.0rc1.tar.xz",
+        "size": 23661916,
+        "sha256": "8707780ae9f19c5bf5b9f27827181ba11cdad7bb292ea49cad5424331e40ee8b",
+        "version": "3.14.0rc1",
         "licenses": ["Python-2.0", "CNRI-Python"],
         "license_file": "LICENSE.cpython.txt",
         "python_tag": "cp314",