update convert_case crate

Summary: as title

Reviewed By: highker

Differential Revision: D62524339

fbshipit-source-id: 622b4c54e5dc46e1965618a9eb4aebedb6a7f40a

vendor/ocaml/interop/rust_to_ocaml/rust_to_ocaml/Cargo.toml

@@ -16,7 +16,7 @@ test = false
 anyhow = "1.0.86"
 attr_parser = { path = "../attr_parser" }
 clap = { version = "3.2.25", features = ["derive", "env", "regex", "unicode", "wrap_help"] }
-convert_case = "0.4.0"
+convert_case = "0.6"
 derive_more = { version = "1.0.0", features = ["full"] }
 indexmap = { version = "2.2.6", features = ["arbitrary", "rayon", "serde"] }
 serde = { version = "1.0.185", features = ["derive", "rc"] }