Issue number: resolves #28963

What is the current behavior?

In #28861 I fixed an issue that caused the wrong content inside of a popover to be scrollable. This CSS should have been applied, but it broke back when popover was converted to the Shadow DOM. Fixing this issue revealed a misconfiguration with the select-popover that caused the select-popover to no longer be scrollable.

What is the new behavior?

Content inside of ion-select-popover can now be scrolled

Note that I am considering this a bug fix instead of a regression. While scrolling used to work in select-popover, it only worked by chance. The .popover-viewport styles should have always applied to the select-popover, thus requiring the use of overflow-y: auto in select-popover.

Does this introduce a breaking change?

Other information

Dev build: 7.7.1-dev.11706893059.1bef4b38