Remove unneeded disabled button on Bio step

We don't require users to have bios, so we shouldn't force them to add one
during the onboarding steps in order to proceed to the next step without
"skipping" it.

app/soapbox/features/onboarding/steps/bio-step.tsx

@@ -17,10 +17,6 @@ const BioStep = ({ onNext }: { onNext: () => void }) => {
   const [isSubmitting, setSubmitting] = React.useState<boolean>(false);
   const [errors, setErrors] = React.useState<string[]>([]);
 
-  const trimmedValue = value.trim();
-  const isValid = trimmedValue.length > 0;
-  const isDisabled = !isValid;
-
   const handleSubmit = () => {
     setSubmitting(true);
 
@@ -79,7 +75,7 @@ const BioStep = ({ onNext }: { onNext: () => void }) => {
                   block
                   theme='primary'
                   type='submit'
-                  disabled={isDisabled || isSubmitting}
+                  disabled={isSubmitting}
                   onClick={handleSubmit}
                 >
                   {isSubmitting ? (