Add some owners to tools/determinism

Currently there are some more people actively working on determinism things.

Derived from
https://chromium-review.googlesource.com/c/chromium/src/+/1183999#message-173c888fec19d325b8f1c8b4a1e8d835b82b52aa

Change-Id: I0306ad04dc0e7cb71592daa5a5005eb423ea4236
Reviewed-on: https://chromium-review.googlesource.com/1184124
Commit-Queue: Sébastien Marchand <sebmarchand@chromium.org>
Reviewed-by: Sébastien Marchand <sebmarchand@chromium.org>
Cr-Commit-Position: refs/heads/master@{#585008}

tools/determinism/OWNERS

@@ -2,6 +2,9 @@
 # https://crbug.com/314403
 
 dpranke@chromium.org
+erikchen@chromium.org
 maruel@chromium.org
 sebmarchand@chromium.org
+thakis@chromium.org
+tikuta@chromium.org
 yyanagisawa@chromium.org