Fix sourcegraph not loading from asset host

What does this MR do?

The Sourcegraph integration has been broken on .com for a while #233447 (closed).

To make matters even stranger, it seems to work for some but not for others. @jeanduplessis and I discovered that there was a different asset being served based on Geo location (see this note). I'm guessing there's an issue with how we replicate assets on the Rails server and making sure we load this from the asset host should fix our problems 😅

This feature is technically behind a feature flag, but the flag has been enabled on .com for a while. For us to know if this will really fix .com issue requires us to "test" in production.com`.

I'm pretty sure this will work...

Screenshots (strongly suggested)

Everything still works locally 😄

Does this MR meet the acceptance criteria?

Conformity

• [ ] Changelog entry Behind feature flag, not needed.
• Documentation (if required)
• Code review guidelines
• Merge request performance guidelines
• Style guides
• Database guides
• Separation of EE specific content

References

Related to #233447 (closed)