Update OWNERS for Weaver

Weaver does not have a clear owner, but list the people who seem to be
most involved with it currently.

Bug: 291284381
Test: N/A
Change-Id: I69de46f8154bf91272a7197ce71c13c745a7208e
(cherry picked from commit f4483a2c)
Merged-In: I69de46f8154bf91272a7197ce71c13c745a7208e