Upgrade public-api

This fixes `cargo xtask public-api` by picking up
https://github.com/aDotInTheVoid/rustdoc-types/commit/577a774c2433beda6.

Cargo.toml

@@ -78,7 +78,7 @@ num_enum = { version = "0.7", default-features = false }
 object = { version = "0.32", default-features = false }
 proc-macro-error = { version = "1.0", default-features = false }
 proc-macro2 = { version = "1", default-features = false }
-public-api = { version = "0.31.2", default-features = false }
+public-api = { version = "0.32.0", default-features = false }
 quote = { version = "1", default-features = false }
 rbpf = { version = "0.2.0", default-features = false }
 rustdoc-json = { version = "0.8.6", default-features = false }