Bug report

When inheriting or implementing a function with an annotated return type array shape, the child functions / function implementations return type cannot have extra keys.

Code snippet that reproduces the problem

Inheritance https://phpstan.org/r/3814321a-eefa-4e2b-acec-7de18138e6a9
Interface https://phpstan.org/r/196b7452-8f31-4e6e-a349-ca35f32f09fb

Expected output

Return value should be able to contain extra keys.

For parameters it should be the other way round.