This commit disables Redis and ActiveSupport instrumentations. They can
still be enabeld when enable some specific environment variables.

Redis one captures all calls to Redis server. As a
typical web request results in numerous Redis calls, this
instrumentation generates more noises. This type of information is
arguably useful. Besides, folks can use the performance bar as a
replacement if they really want to have a deep look to Redis calls.

ActiveSupport instrumentation captures cache-related operations,
including read, write, fetch, delete, to name a few. We use Redis for
caching. It means each operation is duplicated twice. Furthermore, I
don't think cache operations offer any benefits.

Changelog: removed