pw_containers: Add missing dependency
pw_containers: Add missing dependency

pw_polyfill was missing from the GN build.

Change-Id: Id89a5124b2da8e616664a8f288a22587401e76ec
Reviewed-on: https://pigweed-review.googlesource.com/c/pigweed/pigweed/+/108674
Pigweed-Auto-Submit: Wyatt Hepler <cca3bedb37979eacd157a9bceb473582df8aea1e@google.com>
Reviewed-by: Alexei Frolov <a1b001416a8cf9aaea32a3411f8f3c0793ebc0b5@google.com>
Commit-Queue: Auto-Submit <14637eda5603879df170705285bf30f5996692f0@pigweed.google.com.iam.gserviceaccount.com>

google/pigweed,google/pigweed,google/pigweed,google/pigweed,google/pigweed,google/pigweed,google/pigweed,google/pigweed,google/pigweed,google/pigweed