Boston Lyric Opera unveiled its plans for next season recently, and shocked local observers with the announcement that it will trim its schedule of large productions by 25%. Despite the tough economy, the Lyric Opera has thrived over the past decade, and has earned much praise for its artistic leadership. But donations to the Lyric are down significantly, and management decided to trim the season now rather than face a budget crisis later. But not to worry, says the company’s general director: the Lyric plans to expand its season again once finances improve.