Fixing piplines (cargo.lock, clang 16, ubuntu 20.04, CLI11, etc.)

[sezna]

• Commit a lockfile to prevent dependency updates from breaking us
• Remove superfluous toolchain installs in prerequisites.ps1
  • rustup install and rustup toolchain install are the same command
  • we only need to install the toolchain we use in the CI
• Pin cargo-edit version to v0.11.0, which is compatible with our rust version
• Pin backtrace version to v0.3.65
• Updated runtime repo to use clang 16.0.6. Based on this PR for the previous update.

In cargo-land, the semver string x.y.z will actually resolve to anything greater than or equal to x.y.z. It appears that a lot of projects don't consider updating their minimal supported Rust version a breaking change. As we didn't have a lockfile, cargo picked the new patch version with a newer Rust toolchain requirement, which broke us. We should update our Rust version eventually, but I'd consider that a different issue that can be handled in a follow-up PR.

For now, pinning some dependencies has allowed me to generate a compatible lockfile. That lockfile will protect us from this happening again.