vivaldi: 1.9.818.44-1 -> 1.10.867.38-1

- Update to version 1.10.867.38-1
- Drop i386 arch. Vivaldi has suspended support for Linux 32-bit for
  Vivaldi 1.10. Unfortunately, this is due to Chromium suspending support
  for it and maintaining it themselves would take too much resources.
  See https://forum.vivaldi.net/post/142489.
- Update dependency on gtk2 to gtk3.
- Move dependency patchelf from buildInputs to nativeBuildInputs.