Update im-rc requirement from 12.1.0 to 13.0.0

Updates the requirements on [im-rc](https://github.com/bodil/im-rs) to permit the latest version.
- [Release notes](https://github.com/bodil/im-rs/releases)
- [Changelog](https://github.com/bodil/im-rs/blob/master/CHANGELOG.md)
- [Commits](bodil/im-rs@12.1.0...13.0.0)

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

Author: dependabot-support

Cargo.toml

@@ -64,7 +64,7 @@ walkdir = "2.2"
 clap = "2.31.2"
 unicode-width = "0.1.5"
 openssl = { version = '0.10.11', optional = true }
-im-rc = "12.1.0"
+im-rc = "13.0.0"
 
 # A noop dependency that changes in the Rust repository, it's a bit of a hack.
 # See the `src/tools/rustc-workspace-hack/README.md` file in `rust-lang/rust`