The environmental impact report for a proposed 49ers stadium was certified by the Santa Clara City Council early Wednesday morning. The 5-2 vote is a necessary step before a ballot measure can be voted on, and it came hours after Cedar Fair — owner of Great America, which is adjacent to the proposed stadium site — filed a lawsuit that took issue with the term sheet that was signed in June. Ballot language for the June 8 primary is being crafted and will be brought up at next week’s council meeting.