SP native runtimes soon to be removed from polkadot-sdk

[seadanda]

Bench bot runs benchmarks for system parachain runtimes which will soon be removed from the repo in this PR.

When the PR is merged the following system parachain runtimes will be removed:

• asset-hub-kusama and asset-hub-polkadot
• bridge-hub-kusama and bridge-hub-polkadot
• collectives-polkadot
• glutton-kusama

New testing system parachain runtimes will be added:

• collectives-westend
• glutton-westend

The Kusama and Polkadot relay chain runtimes have already been removed from the repo.

I've made the necessary changes to fetchCommandsConfiguration.ts in this repo and the corresponding scripts in command-bot-scripts repo, but for the parsing and guessing I think it's something that I shouldn't decide: i.e. should the bot no longer even attempt to run commands for these runtimes, or should it reply with a reminder that the runtimes in question now live in the polkadot-fellows/runtimes repo?

[mordamax]

@seadanda looks like i can close this, thank you for contribution!