‘I’ve worked here for a year already. It should be clear by now that I’m not a talkative person. This is a question I don’t want to answer. And I hope that you respect that.’

This won’t be taken well at all and sounds incredibly assholish.

‘that I don’t talk doesn’t mean I hate you, it means I have nothing to say’ < I find it ludicrous even having to explain this.

Still kinda rude IMO

‘I don’t see what that has to do with the job’

Depending on the situation could also be rude.

‘I don’t talk about religion, politics or my private life with coworkers and I hope you respect that’

Yes, this is good. Firm and clear.

‘all right, I need time to unwind, which means today I’ll spend my pause somewhere else.’ and proceed to eat alone somewhere else. And if they pester yet again: ‘leave me alone’

How about just “Sorry, I don’t feel like talking right now.” except you say that every time like a broken record. They’ll move on eventually since you never have anything to add.