build(deps): update rcgen requirement from 0.12.0 to 0.13.2

Updates the requirements on [rcgen](https://github.com/rustls/rcgen) to permit the latest version.
- [Release notes](https://github.com/rustls/rcgen/releases)
- [Commits](rustls/rcgen@v0.12.0...v0.13.2)

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

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

poem/Cargo.toml

@@ -155,7 +155,7 @@ unic-langid = { version = "0.9.0", optional = true, features = ["macros"] }
 intl-memoizer = { version = "0.5.1", optional = true }
 ring = { version = "0.17.7", optional = true }
 reqwest = { workspace = true, features = ["json"], optional = true }
-rcgen = { version = "0.12.0", optional = true }
+rcgen = { version = "0.13.2", optional = true }
 x509-parser = { version = "0.16.0", optional = true }
 tokio-metrics = { version = "0.3.0", optional = true }
 rust-embed = { version = "8.0", optional = true }