Re-add non-gzipped files for sourcemaps to support Sentry source fetching

For more context: we were originally uploading the non-gzipped source maps, which was great. However, this MR removed them in order to save some space (~17MB at time of this MR).

I believe the intent in seeing if we can serve gzipped on a request for the non-gzipped file is to retain the benefit of continuing to save space.

If that's not possible, I'd simply motion to re-add the non-gzipped source maps.