[Chapel Merge] Add container for Github CI actions

Notifications Commits
1

Branch: refs/heads/main
Revision: 2f50bff
Author: aconsroe-hpe
Link: Unavailable
Log Message:

Merge pull request #19425 from aconsroe-hpe/ci-in-container

Add container for Github CI actions

reviewed by @ronawho

This adds a Dockerfile for use with our CI actions to reduce their
worst case-execution time by eliminating the need to download dependencies.

This is just phase 1 of 2, where we build the dockerfile and push it
to ghcr (github container registry). The second phase is to actually
use it in CI.yml -- I just don't know how to order these actions
correctly so I'm doing in two PRs

The container image should only get rebuilt when its Dockerfile
changes -- in other words, 99% of PRs shouldn't run this action

Links: