fix docs

Author: Firestar99

crates/cargo-gpu/src/legacy_target_specs.rs

@@ -1,6 +1,6 @@
-//! Legacy target specs are spec jsons for versions before `rustc_codegen_spirv-types` came
-//! bundled with them. Instead, cargo gpu needs to bundle these legacy spec files. Luckily,
-//! they are the same for all versions, as bundling with `rustc_codegen_spirv-types` was
+//! Legacy target specs are spec jsons for versions before `rustc_codegen_spirv_target_specs`
+//! came bundled with them. Instead, cargo gpu needs to bundle these legacy spec files. Luckily,
+//! they are the same for all versions, as bundling target specs with the codegen backend was
 //! introduced before the first target spec update.
 
 use anyhow::Context as _;