Update clap requirement from 2.33 to 3.1 in /ruby/generator

Updates the requirements on [clap](https://github.com/clap-rs/clap) to permit the latest version.
- [Release notes](https://github.com/clap-rs/clap/releases)
- [Changelog](https://github.com/clap-rs/clap/blob/master/CHANGELOG.md)
- [Commits](clap-rs/clap@clap_generate-v3.0.0-rc.0...clap_complete-v3.1.0)

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

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

Author: dependabot[bot]

ruby/generator/Cargo.toml

@@ -7,7 +7,7 @@ edition = "2018"
 # See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
 
 [dependencies]
-clap = "2.33"
+clap = "3.1"
 node-types = { path = "../node-types" }
 tracing = "0.1"
 tracing-subscriber = { version = "0.3", features = ["env-filter"] }