[webcodecs] Shamelessly adding myself to OWNERS

Change-Id: I1a32006dc0d91102b24a16bc591284dc88ca7ab1
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2387415Reviewed-by: Dale Curtis <dalecurtis@chromium.org>
Commit-Queue: Eugene Zemtsov <eugene@chromium.org>
Cr-Commit-Position: refs/heads/master@{#804067}

third_party/blink/renderer/modules/webcodecs/OWNERS

@@ -2,4 +2,5 @@ mlamouri@chromium.org
 sandersd@chromium.org
 dalecurtis@chromium.org
 chcunningham@chromium.org
-tguilbert@chromium.org
+tguilbert@chromium.org
\ No newline at end of file
+eugene@chromium.org
\ No newline at end of file