If the charitable contribution is mandatory, it is not a charitable contribution. If it is not mandatory, very few people (even in CA) will do it.
California should just pass a law that prohibits people from moving out of the state.
Or make them sign a contract that they will continue to pay California taxes.
And if you get something of value from your "charitable" contribution, like football tickets for a contribution to a college then it doesn't count as a charitable contribution. So if you get a state tax credit for the entire amount of the contribution it isn't a charity so no deduction for you.
Maybe California could just build a wall to keep rich people in.
The obvious trick would be to make the state income tax a payroll tax, like the employer portion of Social Security. That way, your W2 income would come already state-tax deducted. So, you could put the entire $10k federal SALT deduction towards your Prop 13 property taxes.
Or maybe you could just move to Nevada.