Update Propshaft to 0.9.x

[aduth]

🛠 Summary of changes

Updates the Propshaft gem to the latest version.

See release notes: https://github.com/rails/propshaft/releases

Specifically, this is aimed at addressing two things:

• A cache invalidation issue we're noticing with desynchronized font URL references, hoping to have been fixed by Digests of files that can have dependencies on other files in the load path need to reflect those dependencies rails/propshaft#188 (v0.9.0)
• Remove the asset fingerprinting shortening monkey-patch added in Override Propshaft digesting for shorter file names #9272, as this appears to be the default as of Shorter digest length rails/propshaft#173 (v0.9.0)

📜 Testing Plan

1. Run rails assets:precompile
2. Run rails s
3. Go to http://localhost:3000
4. Observe no visual defects
5. Open developer tools Elements window
6. Observe assets (e.g. <script> and <link> tags) have digested URLs with a hash of 8 characters (e.g.
   /packs/validated_field_component-5f68c2d7.digested.js)

[aduth]

Looks good on review application as well, which I'd imagine should simulate how this'll behave in a deployed environment.