Allow dead code in component_api fuzz target (#11575)

Fuzz-generation might generate dead types, so this avoids build errors
where types aren't used. Aims to fix [this build log][log]

[log]: https://github.com/bytecodealliance/wasmtime/actions/runs/17335065094/job/49219595286?pr=11570

Author: alexcrichton

fuzz/fuzz_targets/component_api.rs

@@ -1,4 +1,5 @@
 #![no_main]
+#![allow(dead_code, reason = "fuzz-generation sometimes generates unused types")]
 
 use libfuzzer_sys::{arbitrary, fuzz_target};
 use wasmtime_fuzzing::oracles;