chore(deps): update darling requirement from 0.14 to 0.20

Updates the requirements on [darling](https://github.com/TedDriggs/darling) to permit the latest version.
- [Release notes](https://github.com/TedDriggs/darling/releases)
- [Changelog](https://github.com/TedDriggs/darling/blob/master/CHANGELOG.md)
- [Commits](TedDriggs/darling@v0.14.0...v0.20.10)

---
updated-dependencies:
- dependency-name: darling
  dependency-type: direct:production
...

Signed-off-by: dependabot[bot] <[email protected]>

Author: dependabot[bot]

crates/macros/Cargo.toml

@@ -13,7 +13,7 @@ proc-macro = true
 
 [dependencies]
 syn = { version = "1.0.68", features = ["full", "extra-traits", "printing"] }
-darling = "0.14"
+darling = "0.20"
 ident_case = "1.0.1"
 quote = "1.0.9"
 proc-macro2 = "1.0.26"