[owners] Includes infra team as tools owners

Not all infra members are common owners, but own several parts of the
tools directory.

No-Try: true
Change-Id: I48ab2e95b67d13a01a88fef34b86e992da4b9fba
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/3301462
Auto-Submit: Michael Achenbach <machenbach@chromium.org>
Commit-Queue: Liviu Rau <liviurau@chromium.org>
Reviewed-by: Liviu Rau <liviurau@chromium.org>
Cr-Commit-Position: refs/heads/main@{#78083}

tools/OWNERS

 file:../COMMON_OWNERS
-
+file:../INFRA_OWNERS