parseKey is not a function

After updating from 13.0.3 to 13.0.28 I'm getting this error when running `generateApi` from `swagger-typescript-api`

```
undefined:29
const discriminatorKey = parseKey(discriminatorValue)
^

TypeError: parseKey is not a function
at interfaceTemplate (eval at compile (file:///Users/filip/projects/chilipiper/frontend/node_modules/eta/dist/eta.module.mjs:520:12), :29:30)
at eval (eval at compile (file:///Users/filip/projects/chilipiper/frontend/node_modules/eta/dist/eta.module.mjs:520:12), :73:83)
at Array.forEach ()
at eval (eval at compile (file:///Users/filip/projects/chilipiper/frontend/node_modules/eta/dist/eta.module.mjs:520:12), :69:12)
at Module.render (file:///Users/filip/projects/chilipiper/frontend/node_modules/eta/dist/eta.module.mjs:874:42)
at Ie.renderTemplate (file:///Users/filip/projects/chilipiper/frontend/node_modules/swagger-typescript-api/dist/chunk-5FV4QLUU.js:24:10223)
at je.createMultipleFileInfos (file:///Users/filip/projects/chilipiper/frontend/node_modules/swagger-typescript-api/dist/chunk-5FV4QLUU.js:40:2286)
at async je.generateOutputFiles (file:///Users/filip/projects/chilipiper/frontend/node_modules/swagger-typescript-api/dist/chunk-5FV4QLUU.js:40:1096)
at async je.start (file:///Users/filip/projects/chilipiper/frontend/node_modules/swagger-typescript-api/dist/chunk-5FV4QLUU.js:39:3903)
at async vi (file:///Users/filip/projects/chilipiper/frontend/node_modules/swagger-typescript-api/dist/chunk-5FV4QLUU.js:41:4125)
```