Cette expression n’existe pas.

Je pense qu’il s’agit de : « Avoir le sang chaud », qui signifie « s’emporter facilement. »

Without any context, here my two cents (not native speaker). It may refer to the football player

Jadon Malik Sancho. See: https://en.wikipedia.org/wiki/Jadon_Sancho

It may also refer to Sancho Pança (from Don Quichotte).

But it would be “C’est Sancho’ without the definite article.

It’s an expression from Marseille. It’s like saying my brother, my dude, my man. For example, to say "this guy is a really good friend" you can say "lui c’est le sancho".

I hope it helps!