[3.14] gh-139640: Fix swallowing syntax warnings in different modules (GH-139755) (GH-140117)

Revert GH-131993.

Fix swallowing some syntax warnings in different modules if they accidentally
have the same message and are emitted from the same line.

Fix duplicated warnings in the "finally" block.

(cherry picked from commit 279db6bede)

Co-authored-by: Serhiy Storchaka <storchaka@gmail.com>

* Update 2025-10-06-10-03-37.gh-issue-139640.gY5oTb.rst

---------

Co-authored-by: Serhiy Storchaka <storchaka@gmail.com>

Python/_warnings.c

@@ -1479,28 +1479,6 @@ PyErr_WarnExplicitObject(PyObject *category, PyObject *message,
     return 0;
 }
 
-/* Like PyErr_WarnExplicitObject, but automatically sets up context */
-int
-_PyErr_WarnExplicitObjectWithContext(PyObject *category, PyObject *message,
-                                     PyObject *filename, int lineno)
-{
-    PyObject *unused_filename, *module, *registry;
-    int unused_lineno;
-    int stack_level = 1;
-
-    if (!setup_context(stack_level, NULL, &unused_filename, &unused_lineno,
-                       &module, &registry)) {
-        return -1;
-    }
-
-    int rc = PyErr_WarnExplicitObject(category, message, filename, lineno,
-                                      module, registry);
-    Py_DECREF(unused_filename);
-    Py_DECREF(registry);
-    Py_DECREF(module);
-    return rc;
-}
-
 int
 PyErr_WarnExplicit(PyObject *category, const char *text,
                    const char *filename_str, int lineno,