PHILADELPHIA — Rising day care costs could become more affordable under a new bill being introduced in the Senate on Wednesday. The Child and Dependent Care Tax Credit Enhancement Act, written and sponsored by Sen. Bob Casey, D-Pa., would allow working parents to recoup up to half of child care costs, whether from day care centers, after-school programs, summer camps, or less formal arrangements, such as nannies, totaling up to $16,000. It would increase the maximum credit a family can receive for care for a child or dependent person to $4,000 per child, capped at $8,000 in tax credits overall…