Remove react-scripts (SCP-5143)

[ehanna4]

We were alerted by App-sec that the dependency "NTH-check" had a vulnerability that required updating. Further investigation by the team determined NTH-check is occurring in react-scripts and it appears that react-scripts is no longer being maintained. Therefore we opted to remove react-scripts from our code.

Since the team already did a huge chunk of work moving to Vite the lift was not too large to remove react-scripts now.

The changes in this PR were tested locally and on staging. Tests all passed locally, builds built on staging and locally, and running through the release engineering tests on staging all worked as expected.

In removing react-scripts yarn required adding three dependencies around an existing dependency postcss

Testing locally you can pull this branch and run bundle install and yarn install and boot up vite
bin/vite dev
and boot up a local server
./rails_local_setup.rb && source config/secrets/.source_env.bash && bin/rails s
and confirm you can see localhost

[eweitz]

Nice! Related upstream CRA issue: facebook/create-react-app#13186.

Do things work if the new 3 packages are moved from dependencies to devDependencies? If so, that'd enable faster build times, and (theoretically, due to less JS being downloaded and parsed) slightly faster page load times.

[ehanna4]

@eweitz good idea, locally it appears moving the 3 new dependencies to devDependencies does work. I'll make that change and will double check staging once merged

[bistline]

Looks like all the yarn tests are failing with the same import issue:

Cannot find module 'babel-plugin-dynamic-import-node'