Fix: #6820 updating activeStep does not actually change the active st…

…ep (#6841)

* useeffect for active step

* switched to use updateActiveStep and check for valid index

components/lib/stepper/Stepper.js

@@ -2,7 +2,7 @@ import React from 'react';
 import { PrimeReactContext } from '../api/Api';
 import { useHandleStyle } from '../componentbase/ComponentBase';
 import { CSSTransition } from '../csstransition/CSSTransition';
-import { useMergeProps, useMountEffect } from '../hooks/Hooks';
+import { useMergeProps, useMountEffect, useUpdateEffect } from '../hooks/Hooks';
 import { UniqueComponentId, classNames } from '../utils/Utils';
 import { StepperBase } from './StepperBase';
 import { StepperContent } from './StepperContent';
@@ -29,6 +29,12 @@ export const Stepper = React.memo(
             }
         });
 
+        useUpdateEffect(() => {
+            if (props.activeStep >= 0 && props.activeStep <= stepperPanels().length - 1) {
+                updateActiveStep(undefined, props.activeStep);
+            }
+        }, [props.activeStep]);
+
         const getStepProp = (step, name) => {
             return step?.props?.[name];
         };