"Open this line in github" should use permalinks

[asottile-sentry]

Environment

SaaS (https://sentry.io/)

Steps to Reproduce

1. Open an issue from a previous code version where the code has changed around the error location (such as https://sentry.sentry.io/issues/5367399422/?project=1&referrer=github-pr-bot)
2. Click open with github -- in this example the link it produces is https://github.com/getsentry/getsentry/blob/master/getsentry/api/customer_details.py#L252
3. L252 was only correct in the original code revision, the link should look like (taking the revision from the error): https://github.com/getsentry/getsentry/blob/c56be7d4c78e/getsentry/api/customer_details.py#L252 which correctly points at the actual line

Expected Result

^ filled in inline above

Actual Result

^ filled in inline above

Product Area

Issues

Link

https://sentry.sentry.io/issues/5367399422/?project=1&referrer=github-pr-bot

DSN

n/a

Version

n/a