Stop testing beta in the bots (#2824)
Stop testing beta in the bots (#2824)

* disable beta

* try switching on stable

* stable doesn't work for a lot of things now either :-(

* try enabling the main bot
dart-lang/dartdoc,dart-lang/dartdoc,keertip/dartdoc,keertip/dartdoc,dart-lang/dartdoc,keertip/dartdoc,keertip/dartdoc,dart-lang/dartdoc