SAN FRANCISCO — Pacific Gas & Electric Co. is pushing back on a U.S. judge’s revised proposal to prevent the utility’s equipment from causing more wildfires. The company said in a court filing Friday that it could not monitor every tree in its service area at all times to make sure it complies with tree trimming laws. Judge William Alsup in San Francisco earlier this month proposed requiring the company to fully comply with all vegetation management and clearance laws as part of its probation in a criminal case. Alsup called the utility’s efforts to prevent trees from hitting its power lines and starting wildfires dismal. PG&E also objects to Alsup’s proposal to ban it from paying dividends to shareholders until it meets his vegetation management requirements.