[Port dspace-8_x] Remove unused dependencies

[tdonohue]

References

• Backport of Remove unused dependencies #4738 to dspace-8_x

Description

This PR is a backport of #4738 by @alanorth to the dspace-8_x branch. I decided to backport this original PR to avoid dependabot PRs related to these unused dependencies.

It only removes three of the unused dependencies which were verified as unused on the dspace-8_x branch using Knip (similar to the original PR)

• Remove @babel/runtime from package.json
• Remove webpack-dev-server from package.json
• Remove @angular/language-service from package.json

After removing all dependencies, I reran yarn run clean and yarn install to verify the lock file was updated properly.

Instructions for Reviewers

• Verify tests pass
• Verify no change in behavior in dev and production mode

[tdonohue]

👍 Verified no change in behavior on the dspace-8_x branch when running in either production or developer mode.

[tdonohue]

I've tested this backport locally & found no issues with starting the 8.x UI in either dev or production mode. Merging immediately.