The Legislature has approved a casino compact signed by Governor Deval Patrick and the Mashpee Wampanoag tribe. The compact, which promises the state 21.5 percent of gaming revenues if the tribe succeeds in developing a resort casino in Taunton, now heads to Patrick’s desk. The Senate voted, 27 to 9, Thursday in favor of the compact approved last week by the House, and each chamber has given its final procedural approval. Some Southeastern Massachusetts lawmakers had pushed for a compact deadline by which the tribe must earn federal approval to place the land into trust, saying the region could fall behind in casino development if the process drags on too long.