[fuchsia] Fix remaining per-file OWNERS entries to apply to subdirectories

Asterisk ('*') does not match strings that include slashes. Replace such
instances for platform-specific owners with "...".

There were some instances of '*' that really did intend to apply to
files in the current directory or only applied to a single directory.
* //net/base/OWNERS is unchanged
* The entry in //third_party/blink/tools/OWNERS has been moved to a
  subdirectory.

Also removes a non-committer from //skia/OWNERS.

Bug: 1244995
Change-Id: Ife57feee67522d435c80bc545e7a5b16c4a66431
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/3151419
Reviewed-by: Brian Salomon <bsalomon@google.com>
Reviewed-by: Sean Topping <seantopping@chromium.org>
Reviewed-by: Dirk Pranke <dpranke@google.com>
Reviewed-by: Scott Violet <sky@chromium.org>
Reviewed-by: Will Cassella <cassew@google.com>
Reviewed-by: Robert Sesek <rsesek@chromium.org>
Reviewed-by: Wez <wez@chromium.org>
Auto-Submit: David Dorwin <ddorwin@chromium.org>
Commit-Queue: Brian Salomon <bsalomon@google.com>
Cr-Commit-Position: refs/heads/main@{#921223}

• base/OWNERS[diff]
• chromecast/OWNERS[diff]
• content/test/OWNERS[diff]
• media/OWNERS[diff]
• mojo/OWNERS[diff]
• skia/OWNERS[diff]
• third_party/blink/tools/OWNERS[diff]
• third_party/blink/tools/blinkpy/web_tests/port/OWNERS[Added - diff]
• ui/OWNERS[diff]