$ jscodeshift -t removeStoryConfig.js **/*.story.js

input.story.js

export const usePlaceholder = () => (
  <TextField placeholder="I am a placeholder" />
);

usePlaceholder.story = {
  name: 'use placeholder'
};

output.story.js

export const usePlaceholder = () => (
  <TextField placeholder="I am a placeholder" />
);

removeStoryConfig.js

/**
 * @param {import('@types/jscodeshift').FileInfo} fileInfo
 * @param {import('@types/jscodeshift').API} api
 */
module.exports = function(fileInfo, api) {
  return api
    .jscodeshift(fileInfo.source)
    .find(api.jscodeshift.MemberExpression)
    .filter(path => path.value.property.name === 'story')
    .forEach(path => {
      api.jscodeshift(path.parent).remove();
    })
    .toSource({ quote: 'single' });
};