message: Update RELEASE_NOTES for 1.12.1
diff: This file contains one line summaries of commits that are worthy of mentioning in release notes.
  A new header is inserted each time a *tag* is created.
  -## v1.12.2 (currently main branch)
  +## v1.12.3 (currently main branch)
  +
  +## v1.12.2
  ## v1.12.1
  @@ -11,6 +13,7 @@ A new header is inserted each time a *tag* is created.
  Augment model (and view) matrix on `Camera` to accept double precision matrices. When enabled,
  double precision translations allow filament to handle a very large world space.
  [**New API**].
  +- engine: Fix, Views with custom render targets are now blendable.
  ## v1.12.0
  