fix(deps): update rust crate convert_case to ^0.8.0

Author: renovate[bot]

safe-builder-derive/Cargo.toml

@@ -14,4 +14,4 @@ quote = "^1.0"
 proc-quote = "0.3.2"
 syn = { version = "^1.0", features = ["parsing"] }
 proc-macro2 = "^1.0"
-convert_case = "^0.4.0"
+convert_case = "^0.8.0"