gh-115119: Defer removal of bundled libmpdec to 3.16 (#133997)

Rename libmpdecimal -> libmpdec

see https://www.bytereef.org/mpdecimal/doc/libmpdec/index.html

Author: skirpichev

Doc/deprecations/c-api-pending-removal-in-3.15.rst

@@ -1,7 +1,6 @@
 Pending removal in Python 3.15
 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 
-* The bundled copy of ``libmpdecimal``.
 * The :c:func:`!PyImport_ImportModuleNoBlock`:
   Use :c:func:`PyImport_ImportModule` instead.
 * :c:func:`PyWeakref_GetObject` and :c:func:`PyWeakref_GET_OBJECT`:

Doc/deprecations/c-api-pending-removal-in-3.16.rst

@@ -0,0 +1,4 @@
+Pending removal in Python 3.16
+^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+* The bundled copy of ``libmpdec``.

Doc/whatsnew/3.12.rst

@@ -2233,6 +2233,8 @@ Deprecated
 
 .. include:: ../deprecations/c-api-pending-removal-in-3.15.rst
 
+.. include:: ../deprecations/c-api-pending-removal-in-3.16.rst
+
 .. include:: ../deprecations/c-api-pending-removal-in-future.rst
 
 Removed

Doc/whatsnew/3.13.rst

@@ -2546,6 +2546,8 @@ Deprecated C APIs
 
 .. include:: ../deprecations/c-api-pending-removal-in-3.15.rst
 
+.. include:: ../deprecations/c-api-pending-removal-in-3.16.rst
+
 .. include:: ../deprecations/c-api-pending-removal-in-3.18.rst
 
 .. include:: ../deprecations/c-api-pending-removal-in-future.rst
@@ -2592,7 +2594,7 @@ Build Changes
 
 * The :file:`configure` option :option:`--with-system-libmpdec`
   now defaults to ``yes``.
-  The bundled copy of ``libmpdecimal`` will be removed in Python 3.15.
+  The bundled copy of ``libmpdec`` will be removed in Python 3.16.
 
 * Python built with :file:`configure` :option:`--with-trace-refs`
   (tracing references) is now ABI compatible with the Python release build

Doc/whatsnew/3.14.rst

@@ -3053,6 +3053,8 @@ Deprecated
 
 .. include:: ../deprecations/c-api-pending-removal-in-3.15.rst
 
+.. include:: ../deprecations/c-api-pending-removal-in-3.16.rst
+
 .. include:: ../deprecations/c-api-pending-removal-in-3.18.rst
 
 .. include:: ../deprecations/c-api-pending-removal-in-future.rst

configure

@@ -8129,11 +8129,11 @@ PY_STDLIB_MOD([_decimal],
 
 AS_VAR_IF([with_system_libmpdec], [no],
           [AC_MSG_WARN([m4_normalize([
-     the bundled copy of libmpdecimal is scheduled for removal in Python 3.16;
+     the bundled copy of libmpdec is scheduled for removal in Python 3.16;
      consider using a system installed mpdecimal library.])])])
 AS_IF([test "$with_system_libmpdec" = "yes" && test "$have_mpdec" = "no"],
       [AC_MSG_WARN([m4_normalize([
-         no system libmpdecimal found; falling back to pure-Python version
+         no system libmpdec found; falling back to pure-Python version
          for the decimal module])])])
 
 PY_STDLIB_MOD([_dbm],