Users are typically familar with the way their screen reader announces domain names. Various screen readers have user settings to control verbosity, including some for punctuation.
As an author (or developer) you shouldn't try to force a screen reader to announce the punctuation. It's their screen reader, not yours.
Note that an aria-label is conveyed to assistive technology in general - it isn't just for text-to-speech output. These labels are also conveyed via Braille displays too, and can also affect how speech control (dictation input) behaves. Beware of trying to use ARIA to influence how a link sounds in a screen reader, because you can make things worse for braille output and speech control users.