build(deps): Update rootcause-backtrace requirement (#36)

Updates the requirements on [rootcause-backtrace](https://github.com/rootcause-rs/rootcause) to permit the latest version.
- [Release notes](https://github.com/rootcause-rs/rootcause/releases)
- [Changelog](https://github.com/rootcause-rs/rootcause/blob/main/CHANGELOG.md)
- [Commits](rootcause-rs/rootcause@v0.11.1...v0.12.0)

---
updated-dependencies:
- dependency-name: rootcause-backtrace
  dependency-version: 0.12.0
  dependency-type: direct:production
...

Signed-off-by: dependabot[bot] <support@github.com>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

Author: dependabot[bot]

backpack/cli/Cargo.toml

@@ -21,7 +21,7 @@ tracing = { workspace = true }
 tracing-subscriber = { version = "0.3.22", features = ["env-filter", "json"] }
 terminal-banner = { workspace = true }
 rootcause = "0.12.0"
-rootcause-backtrace = "0.11.1"
+rootcause-backtrace = "0.12.0"
 tokio = { workspace = true }
 env-rs = { git = "https://github.com/yonasBSD/env.rs", version = "0.1.0" }