gh-108444: Replace _PyLong_AsInt() with PyLong_AsInt() (#108459)

Change generated by the command:

sed -i -e 's!_PyLong_AsInt!PyLong_AsInt!g' \
    $(find -name "*.c" -o -name "*.h")

Objects/unicodeobject.c

@@ -14034,7 +14034,7 @@ unicode_format_arg_parse(struct unicode_formatter_t *ctx,
                                 "* wants int");
                 return -1;
             }
-            arg->prec = _PyLong_AsInt(v);
+            arg->prec = PyLong_AsInt(v);
             if (arg->prec == -1 && PyErr_Occurred())
                 return -1;
             if (arg->prec < 0)