fix(eslint): Remove unnecessary type assertions

Removed unnecessary type assertions that were flagged by ESLint:
- inputField.tsx: Removed `as any` from e.target.value
- numberField.tsx: Removed `as any` from e.target.value
- onboarding.tsx: Removed `as number` assertions from stepper onClick handler

These assertions were unnecessary because TypeScript already infers the correct
types from the event handlers and component props.

Author: dashed

static/app/components/forms/fields/inputField.tsx

@@ -49,7 +49,7 @@ function defaultField({
     <InputGroup>
       <InputGroup.Input
         onBlur={e => onBlur(e.target.value, e)}
-        onKeyDown={e => onKeyDown((e.target as any).value, e)}
+        onKeyDown={e => onKeyDown(e.target.value, e)}
         onChange={e => onChange(e.target.value, e)}
         name={name}
         {...rest}

static/app/components/forms/fields/numberField.tsx

@@ -62,7 +62,7 @@ function createFieldWithSuffix({suffix}: {suffix: React.ReactNode}) {
       <InputGroup>
         <InputGroup.Input
           onBlur={e => onBlur(e.target.value, e)}
-          onKeyDown={e => onKeyDown((e.target as any).value, e)}
+          onKeyDown={e => onKeyDown(e.target.value, e)}
           onChange={e => onChange(e.target.value, e)}
           name={name}
           {...rest}

static/app/views/onboarding/onboarding.tsx

@@ -215,12 +215,12 @@ export function OnboardingWithoutContext(props: Props) {
             numSteps={onboardingSteps.length}
             currentStepIndex={stepIndex}
             onClick={i => {
-              if ((i as number) < stepIndex && shallProjectBeDeleted) {
-                handleGoBack(i as number);
+              if (i < stepIndex && shallProjectBeDeleted) {
+                handleGoBack(i);
                 return;
               }
 
-              goToStep(onboardingSteps[i as number]!);
+              goToStep(onboardingSteps[i]!);
             }}
           />
         )}