Slack Discover Preview shows different interval visualization than graphed query in Sentry

### Environment

SaaS (https://sentry.io/)

### Steps to Reproduce

1. Create a discover query with Bar Chart display type and 1h interval
2. Copy the link and paste it in Slack

### Expected Result

I would expect the Bar Chart visualization in the Slack preview to have the same bar chart series as the discover query created

### Actual Result

The bar chart series in the slack preview are finer, more granular than the discover query created

### Product Area

Discover

### Link

_No response_

### DSN

_No response_

### Version

_No response_

Reproduce the issue in Sentry SaaS by creating a Discover Bar Chart query with a 1h interval, then opening its Slack preview. Compare the preview's bar series with the original query and trace the interval used by each; done means both visualizations use the same interval and series.

Written by the indexing model from the issue text.