Does not build with `transformers-0.6.*` (GHC 9.6)

[RyanGlScott]

Currently, language-rust imposes upper version bounds of <0.6 on transformers:

https://github.com/harpocrates/language-rust/blob/9d509c450d009cc99f1180b3f2f30247dfb1cfce/language-rust.cabal#L89

This prevents it from building with transformers-0.6.*. As this is the version of transformers that is bundled with GHC 9.6, this makes it difficult to build language-rust with GHC 9.6.