Hide "Create Github Issue" Button

### Problem Statement

We don't use GitHub issues but by using the GitHub integration we always get a "Create Github Issue" button on top of the "Create JIRA Issue" button. This can be confusing for people and add clutter to the UI. We have GitHub issues disabled in our project.

### Solution Brainstorm

What we'd want: Let us manually disable this feature on the integration.
How we can mitigate: You get an error when trying to create a github issue through Sentry, so there is no risk in people actually creating issues in two places. The issue is just clutter.

### Product Area

Other