Pyttsx, mbrola, mimic 3. I like the mimic 3. Which is lightweight. And can run on docker or just native.

I started out with mycroft which has mimic 3 build in. But you can run it just stand alone as well and quite easy to set up. https://mycroft.ai/mimic-3/

If you want to go down the rabbithole of speech synthesis and analsys check out praat praat.org it's a quiet impressive piece of software.