feat(action): add save-always input

[BlackHole1]

Ref:

• https://github.com/actions/cache/blob/81382a721fc89d96eca335d0c3ba33144b2baa9d/action.yml#L40
• https://github.com/actions/cache/commit/b1378c8403e6779ec61a229f419bc68c0e118f02