[keyserver] Revert D4422 and D4429

Summary: Relevant Linear issue here. This diff reverts D4422 and D4429 after issues arose with source-nvm.sh resulting in the wrong Node version being used.

Test Plan: Ran the Docker keyserver build and since this is a reverting change, things should work as they did before.

Reviewers: atul, ashoat

Reviewed By: ashoat

Subscribers: Adrian

Differential Revision: https://phab.comm.dev/D4526