We've recently introduced a cache for agent tokens created by `glab cluster agent get-token` (this is a Kubernetes credential plugin used when configuring with `glab cluster agent update-kubeconfig`). This cache is currently a black box to our users. A new set of commands should allow to list the tokens in the cache and to clear and / or revoke them. ## Implementation Plan - Implement a new `token-cache` command group under `glab cluster agent`. - Implement a new `token-cache` subcommand called `list` to list all available tokens. By default this command shows the cached tokens in the keyring and file system cache. A `--filestsyem=true/false` and `--keyring=true/false` flag should make this configurable. For `--keyring` (or keyring in general) to work, we first need to fetch all available agents of the project (from --repo) or allow to specify them via `--agent`. - Implement a new `token-cache` subcommand called `clear` to remove all locally cached tokens. Have `--filesystem` and `--keyring` flags similar to the `list` command. Have a `--revoke` flag to automatically revoke the cleared tokens. (or rather a `--no-revoke` to opt out. Revoking is probably the better default behavior).