There isn't really a way to prevent this behaviour outright. What I'd advise is getting some outdoor lights if you can as any sort of motion-triggered lighting is a reasonable deterrent. I know some people recommend floodlights that stay on all night, too. If you don't have any CCTV system in place, I'd advise a video doorbell if it points towards your car as they're also motion-triggered and could be a useful piece of kit to catch anyone in the act. Call 999 and report it if you see anyone actually doing it. Call 101 if you have them on camera as I believe the police sometimes patrol areas where there have been various similar reports of attempted theft and damage.

I'm afraid we can't offer much more advice, but when we're out of lockdown, it may also be worth speaking to your neighbours, too. There's a smartphone app called Nextdoor which is essentially a social media site for your local area (the surrounding neighbourhoods, for example). It's very handy for staying in the loop with your neighbours as you never know who might see something useful. Lastly, very obvious, but make sure your car is always locked and if it has keyless entry - keep the keyfob away from doors and windows (and/or put them in a faraday bag) so they can't steal it via keyless theft.

As a last resort, you could Google some products that won't damage the paintwork and apply them to the door handles. I don't know if I'd personally go this route, but I'm not sure they'll keep trying the handles if they end up with something unpleasant on their hands next time.