Give build team global OWNERS for .pydeps files

These by nature pick up transitive deps, so it doesn't really make sense
to require per-team OWNERS when a //build .py gains a new dep.

Bug: None
Change-Id: I98be08e3c40ae5d4913d7806379cd38434a6363a
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2484264
Auto-Submit: Andrew Grieve <agrieve@chromium.org>
Reviewed-by: Yaron Friedman <yfriedman@chromium.org>
Commit-Queue: Yaron Friedman <yfriedman@chromium.org>
Cr-Commit-Position: refs/heads/master@{#818454}

OWNERS

@@ -24,6 +24,7 @@ per-file PRESUBMIT*.py=dpranke@google.com
 per-file PRESUBMIT*.py=jochen@chromium.org
 per-file README.md=*
 per-file WATCHLISTS=*
+per-file *.pydeps=file://build/OWNERS
 per-file *.gn=file://build/OWNERS
 per-file *.gni=file://build/OWNERS
 per-file *fuzzer.*=file://testing/libfuzzer/OWNERS