Workaround a release blocker after libc++ change (#43091)

The code breaks in C++20 mode after libc++ removes comparisons for `std::vector` and replaces them with 'operator <=>'.

See cl/542541552 for context.
https://dart.googlesource.com/external/github.com/flutter/engine/+/a3c5a319fccb7b137949ee7f410bf2510148dd3d
1 file changed
tree: 43d1208f5f3f618bfbf0620e0b96d37f9049534c
  1. commits.json