GH-94851: fix immortal objects refcounting in compiler (gh-95040)

(cherry picked from commit 7476154)

Co-authored-by: Kumar Aditya <[email protected]>

Author: miss-islington

Python/compile.c

@@ -4912,7 +4912,7 @@ compiler_joined_str(struct compiler *c, expr_ty e)
     Py_ssize_t value_count = asdl_seq_LEN(e->v.JoinedStr.values);
     if (value_count > STACK_USE_GUIDELINE) {
         _Py_DECLARE_STR(empty, "");
-        ADDOP_LOAD_CONST_NEW(c, &_Py_STR(empty));
+        ADDOP_LOAD_CONST_NEW(c, Py_NewRef(&_Py_STR(empty)));
         ADDOP_NAME(c, LOAD_METHOD, &_Py_ID(join), names);
         ADDOP_I(c, BUILD_LIST, 0);
         for (Py_ssize_t i = 0; i < asdl_seq_LEN(e->v.JoinedStr.values); i++) {