Add `cargo ci` alias for `ci` tool

[BD103]

Objective

• Running cargo run --package ci -- ... is lengthy, and cargo r -p ci -- ... isn't much better.
• Closes #13197.

Solution

• Add an opt-in alias to the ci tool with cargo ci ....
  • You need to copy config_fast_builds.toml to config.toml to enable this functionality.

Testing

• Copy config_fast_builds.toml to config.toml, then run cargo ci --help.

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Changelog

• Added cargo ci alias for internal ci tool.

[BD103]

It's unfortunate that this is opt-in, but this is the least-friction solution. The alternative probably would involve:

• Renaming config_fast_builds.toml to config.toml, breaking a few links on the website.
• Remove config.toml from .gitignore.
• Disable all of the fast-build shenanigans by default.

The issue with that is that all changes to config.toml, such as enabling fast builds, would be tracked by Git. I feel like that would interfere with the development workflow too much that it does not justify the change.

[Brezak]

Given #13279. Could we add a setup command to our CI tool that asks the contributor some questions and then setups the config.toml for them?

[BD103]

That sounds like a great follow-up PR! I'll create an issue for it.