Bump cargo-vet to 0.5. (#6029)

Aside from a few new features (notably automatic registry suggestions), this
release removes the need to import description for criteria that are not
directly used, and adds an explicit version to the cargo-vet instance.

supply-chain/config.toml

@@ -1,6 +1,9 @@
 
 # cargo-vet config file
 
+[cargo-vet]
+version = "0.5"
+
 [imports.chromeos]
 url = "https://chromium.googlesource.com/chromiumos/third_party/rust_crates/+/main/cargo-vet/audits.toml?format=TEXT"