ci(devcontainer-base): use the unpinned local candidate

Author: robarnold

.github/workflows/image-devcontainer-base.yml

@@ -50,11 +50,6 @@ jobs:
           load: true
           push: false
           tags: ghcr.io/${{ github.repository_owner }}/devcontainer-base:latest
-      - name: Select Candidate Image
-        run: |
-          sed -i \
-            's|^FROM ghcr.io/marinatedconcrete/devcontainer-base:latest.*$|FROM ghcr.io/marinatedconcrete/devcontainer-base:latest|' \
-            .devcontainer/Containerfile
       - name: Validate Downstream Checks
         uses: devcontainers/ci@513af61f4de4f75d37e4438f184ba4358f0fc1ca # v0.3.1900000450
         with: