A Lagunitas School District parent is among 21 plaintiffs suing the State of California, the state’s departments of education and public health to block a law passed last year that outlaws personal-belief exemptions for school-required, childhood vaccinations. Filed on July 14 by attorneys based in Washington, D.C., Wyoming and California, the lawsuit marks the latest effort to beat back tighter school enrollment restrictions that many expect will prompt an exodus of families unwilling to fully…