Bridgestone Potenza S001 originally, now Conti Sport Contact 6.
Since all weather tyres/winter tyres aren’t mandatory in the UK, there’s no reason for a manufacturer to not fit summer tyres. Sucks, but is what it is.
I don’t think there’s many, if at all manufacturers who fit M/S tyres from factory (unless they offer the option to do so).
Prior: SEAT Ateca Xcellence Lux 1.5 TSI DSG MY19, VW Golf GTE PHEV DSG MY23
Current: Hyundai Ioniq 6 Ultimate
Next: we'll see what's available in 2028.