Remove devcontainer-ci.json and update lint-test-build workflow to build Docker image directly

.devcontainer/devcontainer-ci.json

@@ -1,11 +0,0 @@
-// For the moment --platform is not supported in devcontainers/ci when
-// using docker compose, so in this devcontainer config file we are
-// using the Dockerfile directly to run actions in CI.
-//
-// https://github.com/devcontainers/cli/issues/404
-{
-  "build": {
-    "context": "../",
-    "dockerfile": "../docker/Dockerfile.dev"
-  }
-}