codex: fix CI failure on PR #16805

Ignore the workspace `opus` dependency in cargo-shear for core_test_support because Rust imports that package as `audiopus`.

Co-authored-by: Codex <noreply@openai.com>

codex-rs/core/tests/common/Cargo.toml

@@ -47,3 +47,7 @@ zstd = { workspace = true }
 [dev-dependencies]
 pretty_assertions = { workspace = true }
 reqwest = { workspace = true }
+
+[package.metadata.cargo-shear]
+# Imported as `audiopus` from Rust code, but declared as `opus` in workspace deps.
+ignored = ["opus"]