CC-2075: Update Rust to 1.92

[andy1li]

Note

Upgrades the Rust toolchain to 1.92 across templates and examples, and provides a matching build environment.

• Updates buildpack to rust-1.92 in codecrafters.yml (compiled starter and solution folders)
• Bumps required cargo version to 1.92 in READMEs and starter_templates/rust/config.yml
• Adds dockerfiles/rust-1.92.Dockerfile for the new toolchain and sets build cache/deps paths

^{Written by Cursor Bugbot for commit 9c71491. This will update automatically on new commits. Configure here.}

[linear]

CC-2075 Update to Gleam version 1.13.0