Revert "[infra] Flutter bot should sync to origin/skia-master"

This reverts commit 8061053b73e217b648d33e0da09d9cb3725b6ae3.

Reason for revert: skia-master branch no longer exists

Original change's description:
> [infra] Flutter bot should sync to origin/skia-master
> 
> Bug: skia:
> Change-Id: I223bef522ff8605674f4ecabcbd0624cfc92cb06
> Reviewed-on: https://skia-review.googlesource.com/c/173224
> Reviewed-by: Ravi Mistry <rmistry@google.com>
> Commit-Queue: Eric Boren <borenet@google.com>

TBR=borenet@google.com,rmistry@google.com

# Not skipping CQ checks because original CL landed > 1 day ago.

Bug: skia:
Change-Id: I3a40a0c6f4a354650d354f2eb4f9d20defe70a0a
Reviewed-on: https://skia-review.googlesource.com/c/178023
Reviewed-by: Ravi Mistry <rmistry@google.com>
Commit-Queue: Ravi Mistry <rmistry@google.com>
3 files changed