Remove testing code

Author: connorjward

.github/workflows/pr.yml

@@ -13,13 +13,3 @@ jobs:
       # Only run macOS tests if the PR is labelled 'macOS'
       test_macos: ${{ contains(github.event.pull_request.labels.*.name, 'macOS') }}
     secrets: inherit
-
-  # UNDO ME
-  docker:
-    name: Build developer Docker containers
-    uses: ./.github/workflows/docker.yml
-    with:
-      tag: connorjwardtest-dev-${{ github.base_ref }}
-      branch: ${{ github.base_ref }}
-      build_dev: true
-    secrets: inherit