Make the Beaker workspace faster

[dirkgr]

In #315, we slowed down the beaker workspace so as to not overwhelm the Beaker service. Beaker has an issue where it is quickly overwhelmed with metadata requests: https://github.com/allenai/beaker/issues/2238

When the Beaker team resolves that issue, we should revert #315, or at least find a higher limit.