SACRAMENTO, Calif.— PG&E Corp. spent nearly $4.9 billion last year to prevent wildfires — and still wound up responsible for the second-largest fire in California history. This year it plans to raise its wildfire safety budget to almost $6 billion. California’s largest utility filed its 2022 “wildfire mitigation plan” with state regulators Friday, offering a blueprint for how it intends to reduce risk at a time of climate change and drought. The budget for 2022 is expected to hit $5.96 billion. Perhaps its most ambitious initiative is an accelerated effort to bury electricity lines underground…