[Core] Activate live linting in codespaces (#3293)

* [Core] Add live linting to devcontainer

* Deactivate lint on type

.devcontainer/Dockerfile

@@ -4,4 +4,5 @@ RUN  apt-get update && \
     apt-get install --yes --no-install-recommends \
       git && \
     pecl install xdebug && \
+    pear install PHP_CodeSniffer && \
     docker-php-ext-enable xdebug