test-interactive: Run thanos-rule-syncer

[jessicalins]

Currently, when running make test-interactive we can create/list rules via the api/v1/rules/raw endpoint.

However, we are not able to see those rules synced in api/v1/rules endpoint, because we don't run an instance of thanos-rule-syncer.

Adding this can improve user experience in general and allows a more complete testing flow (suggested by @kyoto)