Add myself to OWNERS since I'm maintaining this package.

E.g. see
https://chromium.googlesource.com/deps/inspector_protocol/+log

Change-Id: I0b38d2813bbe99be2bcce12390369e57125e728d
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1991804Reviewed-by: Dmitry Gozman <dgozman@chromium.org>
Commit-Queue: Johannes Henkel <johannes@chromium.org>
Cr-Commit-Position: refs/heads/master@{#65648}

third_party/inspector_protocol/OWNERS

@@ -4,3 +4,4 @@ dgozman@chromium.org
 kozyatinskiy@chromium.org
 pfeldman@chromium.org
 yangguo@chromium.org
+johannes@chromium.org