Add error handling for lockfile API of cargo-gpu-build

Author: tuguzT

Cargo.lock

@@ -10,7 +10,7 @@ license.workspace = true
 [dependencies]
 rustc_codegen_spirv-cache = { path = "../rustc_codegen_spirv-cache" }
 spirv-builder.workspace = true
-anyhow.workspace = true
+thiserror.workspace = true
 semver.workspace = true
 log.workspace = true
 

crates/cargo-gpu-build/Cargo.toml

@@ -12,7 +12,6 @@
 //! to pass the many additional parameters required to configure rustc and our codegen backend,
 //! but provide you with a toolchain-agnostic version that you may use from stable rustc.
 
-#![expect(clippy::missing_errors_doc, reason = "temporary allow this")] // TODO: remove this & fix documentation
 #![expect(clippy::pub_use, reason = "part of public API")]
 
 pub use rustc_codegen_spirv_cache as spirv_cache;