Calls to /apps use etag even though Endpoint does not support it

There is an issue in API where the etag for paginated items is not generated. Due to this the same the heroics client will always see a 304 from the /apps endpoint and always return the same list even if things have changed.

Here's an internal ticket about the issue:
https://github.com/heroku/api/issues/7691

This is a blocker to upgrade the Ruby buildpack and Java Buildpack test suites away from v2 of the API.

Wondering if we could add some kind of an option or method invocation to disable etag checking for certain calls, that would work around the issue in the short term.