If you’re in the Scheme, nothing will change. You can carry on contributing to your pension savings and your employer will carry on contributing too, until you decide to start taking your retirement benefits (or transfer out).
If you’re not in the Scheme, you can ask to join until you reach age 74, as long as you’re an entitled or non-eligible jobholder. See Who is an entitled jobholder? and Who is an eligible jobholder?