[Uptime] Infinite requests for index pattern

[justinkambic]

Kibana version:
master

Elasticsearch version:
yarn es snapshot

Server OS version:
macOS

Browser version:
Chrome 79.*

Browser OS version:
macOS

Original install method (e.g. download page, yum, from source, etc.):
from source

Describe the bug:
There's an issue where the Uptime Overview page makes an infinite series of requests to the index pattern API endpoint.

Steps to reproduce:

1. Open browser console
2. Navigate to Uptime
3. Observe the issue

Expected behavior:
There would be a single request for the index pattern.

Screenshots (if relevant):

Errors in browser console (if relevant):
N/A

Provide logs and/or server output (if relevant):
N/A

Any additional context:
This is due to the inclusion of a setter from useState as a dependency of the useEffect used by our useIndexPattern hook. As a temporary fix, we should ignore the eslint rule for this line, and remove that function as a dependency of the hook. Longer term, we should migrate away from individual components being responsible to fetch this.

[elasticmachine]

Pinging @elastic/uptime (Team:uptime)