The sun is setting on Evergreen Solar, whose green-energy business fizzled even though Gov. Deval Patrick’s administration showered the Marlboro company with $58 million in subsidies and tax breaks. Evergreen, which made solar-power panels, cut about half of its 133 remaining employees and sought bankruptcy protection after concluding that it couldn’t compete with low-cost Chinese manufacturers. The company had already shifted some work to China last year in a cost-cutting move, then closed its Devens factory in March and eliminated 800 jobs.