Speed up the SAASBO tutorial (#1740)

Summary:
Speed up the SAASBO tutorial by using 256 warmup steps and 128 samples (with a comment that we still recommend 512 warmup steps and 256 samples). I also dropped the dimensionality of the problem from 50 to 30 and increased the batch size from 4 to 5. The tutorial now runs in ~12 minutes on Github Actions.

Pull Request resolved: #1740

Reviewed By: esantorella

Differential Revision: D44092726

Pulled By: dme65

fbshipit-source-id: 3bd8f627f46394b5f68a1019f4593ad4bade56e9

Author: dme65

scripts/run_tutorials.py

@@ -28,8 +28,6 @@
     "thompson_sampling.ipynb",  # very slow without KeOps + GPU
     "composite_mtbo.ipynb",  # TODO: very slow, figure out if we can make it faster
     # Timing out in standard mode
-    "saasbo.ipynb",
-    # Timing out in standard mode
     "scalable_constrained_bo.ipynb",
 }