[eslint config] [base] [breaking] enable `no-mixed-operators` rule.
[eslint config] [base] [breaking] enable `no-mixed-operators` rule.

Specifically, this is to require parens to avoid cognitive overhead about precedence.
ljharb/javascript,LodoSoftware/javascript-style-guide,addshoppers/javascript,bl00mber/javascript,getjll/JavaScript-Style-Guide,cloudability/javascript-style-guide,practicefusion/javascript,pokelondon/javascript,webcoding/javascript-style-guide,appcom-interactive/javascript,xalexec/javascript,codelegant/JavaScript,allanfish/javascript,naustudio/javascript,airbnb/javascript,whichdigital/javascript-coding-standards,naustudio/javascript,LodoSoftware/javascript-style-guide,codelegant/JavaScript,nulogy/javascript