BRUSSELS — The European Commission on Friday announced an investigation into Slovakia over the dismantling of its whistleblower protection office. In its latest rule-of-law spat with Bratislava, the EU executive criticized leftist-populist leader Robert Fico for trying to replace the office with a new institution whose leadership would be politically appointed. “The Commission considers that this law breaches EU rules,” it wrote in an official note on Friday. Brussels’ move comes amid strong