The Baker administration on Tuesday announced $2.15 million in grants to help companies create shared workspaces in Massachusetts, part of a growing trend of support for artists and entrepreneurs. Lt. Gov. Karyn Polito joined Holyoke Mayor Alex Morse at Gateway City Arts to announce the second round of grants under the Collaborative Workspaces Program, run by MassDevelopment. The funding includes $1.5 million in state money and $645,000 from the Barr Foundation, a Boston-based nonprofit organization. The Barr Foundation has pledged to contribute nearly $2 million over the next three years for arts-related collaborative workspaces.