Bug - Slider- use token instead for hard coded value

[tlabaj]

Use a token instead of the hard coded value for --pf-v5-c-slider__step--Left

patternfly-react/packages/react-core/src/components/Slider/SliderStep.tsx

Line 29 in 52cbf11

const style = { '--pf-v5-c-slider__step--Left': `${value}%` } as React.CSSProperties;

Follow up to core patternfly/patternfly#5892