Background
Removing MetricsClient#dispatch() requires removing EventLogging::submitMetricsEvent(), which proxies to it.
Acceptance Criteria
- EventLogging::submitMetricsEvent() is removed
- Unit/integration tests covering the method are removed
Notes
- There are no uses of EventLogging::submitMetricsEvent() in any codebase indexed by Codesearch: https://codesearch.wmcloud.org/search/?q=::submitMetricsEvent\(