medusa: medusa-source-shopify plugin not working

Bug report

Describe the bug

medusa-source-shopify is not working. Getting the The class must be a valid service implementation error on yarn start once I yarn add medusa-source-shopify and add the required configuration for the plugin.

✔ Models initialized – 11ms
✔ Plugin models initialized – 3ms
✔ Repositories initialized – 33ms
✔ Strategies initialized – 20ms
✔ Modules initialized – 0ms
✔ Database initialized – 80ms
✔ Services initialized – 7ms
✔ Express intialized – 5ms
⠋ Initializing plugins
error:   The class must be a valid service implementation, please check backend/node_modules/medusa-source-shopify/services/shopify-cache.js
error:   The class must be a valid service implementation, please check backend/node_modules/medusa-source-shopify/services/shopify-client.js
error:   The class must be a valid service implementation, please check backend/node_modules/medusa-source-shopify/services/shopify-collection.js
error:   The class must be a valid service implementation, please check backend/node_modules/medusa-source-shopify/services/shopify-product.js
error:   The class must be a valid service implementation, please check backend/node_modules/medusa-source-shopify/services/shopify-redis.js
error:   The class must be a valid service implementation, please check backend/node_modules/medusa-source-shopify/services/shopify.js
Error: The class must be a valid service implementation, please check backend/node_modules/medusa-source-shopify/services/shopify-cache.js
    at backend/node_modules/@medusajs/medusa/dist/loaders/plugins.js:357:51
    at step (backend/node_modules/@medusajs/medusa/dist/loaders/plugins.js:33:23)
    at Object.next (backend/node_modules/@medusajs/medusa/dist/loaders/plugins.js:14:53)
    at backend/node_modules/@medusajs/medusa/dist/loaders/plugins.js:8:71
    at new Promise (<anonymous>)
    at __awaiter (backend/node_modules/@medusajs/medusa/dist/loaders/plugins.js:4:12)
    at backend/node_modules/@medusajs/medusa/dist/loaders/plugins.js:344:87
    at Array.map (<anonymous>)
    at backend/node_modules/@medusajs/medusa/dist/loaders/plugins.js:344:60
⠧ Initializing plugins

System information

Medusa version (including plugins): 
  "dependencies": {
    "@medusajs/medusa": "^1.6.0",
    "@medusajs/medusa-cli": "^1.3.3",
    "medusa-fulfillment-manual": "^1.1.31",
    "medusa-interfaces": "^1.3.3",
    "medusa-payment-manual": "^1.0.16",
    "medusa-payment-stripe": "^1.1.45",
    "medusa-source-shopify": "^1.2.8-ci-issue-20230322190222",
    "typeorm": "^0.2.36"
  },

Node.js version: v16.19.0 Database: postgres Operating system: Mac OS 13.2.1 (22D68)