Clean up the pubspec.yaml in analysis_server
Clean up the pubspec.yaml in analysis_server

There is already a normal dependency on html, so the dev dependency isn't
needed.

Change-Id: Ib4c599c5894022a8bbeca4374cdd3c9a77d3fea1
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/159300
Reviewed-by: Konstantin Shcheglov <09e4d7516628963212bf4aace2f97603d2b706e4@google.com>
Commit-Queue: Brian Wilkerson <1f7641b6b14c52b9163524ab8d9aabff80176f21@google.com>

dart-lang/sdk,dart-lang/sdk,dart-lang/sdk,dart-lang/sdk,dart-lang/sdk,dart-lang/sdk,dart-lang/sdk,dart-lang/sdk