remove bootsnap #2247
Description
In 32f888e the dependency bootsnap was added as part of #1882, presumably to improve the boot time of the application.
However, the PR doesn't mention anything about this dependency, nor does it provide any data showing that it actually makes a difference.
AFAICT the cache is only stored locally, and the Heroku apps will be starting from empty. That would actually make the app start slower in Heroku.
I propose that we remove this dependency to make the overall setup smaller and simpler, even if it means that the boot time locally is increased a bit.