What was happening before is that we built the webpack bundles in
tools/minify-js with nicely hashed filenames, and then `manage.py
collectstatic` was extending these filenames with a second hash
through the use of storage.
Removing the first one didn't seem ideal, but would probably have
worked, but seems confusing for people only familiar with webpack
(ideally, we want the Django toolchain piece to be increasingly
invisible as we replace it).
And we can't exclude the webpack bundles from being processed by
storage, since we need these bundles to be included in the manifest.
So, instead, we set the hash function to be a no-op for the bundle
files.
Fixes significant portions #5971.
More work is required to deal with versioning for some of the
image/font assets.
Tim Abbott