PG&E Corp. scored a legal victory over federal regulators that could clear the way for the financially troubled utility to rip up billions of dollars in expensive green-power contracts as it seeks to exit bankruptcy. The ruling by Judge Dennis Montali, who is presiding over PG&E’s chapter 11 proceeding, may allow the company to get out of $42 billion in power-purchase agreements, including many pioneering wind and solar deals that are now well above current market prices. …