test: delete firebase resolution tests

We have more generic tests that cover path mappings.

Also, currently these are failing as we use a very old firebase version which doesn’t compile anymore.

https://app.circleci.com/pipelines/github/angular/angular-cli/25915/workflows/efa3cfcf-b609-43bd-a307-ee2997f05088/jobs/340445/parallel-runs/3/steps/3-105

Author: alan-agius4