failed postman json import - "The URI does not contain a valid specification"

### Expected Behavior

This feature used to work, but it looks like Postman changed their exported data structure and broke the import into Insomnia.

### Actual Behavior

We are greeted with the message: **The URI does not contain a valid specification** with the following stack trace:
```js
Error: No importers found for file
at Jge (file:///Applications/Insomnia.app/Contents/Resources/app.asar/index.a1e8765b.js:80:42986)
at async uI (file:///Applications/Insomnia.app/Contents/Resources/app.asar/index.a1e8765b.js:80:43935)
at async sE (file:///Applications/Insomnia.app/Contents/Resources/app.asar/index.a1e8765b.js:80:43397)
at async Yz (file:///Applications/Insomnia.app/Contents/Resources/app.asar/index.a1e8765b.js:125:8948)
```

### Reproduction Steps

1. Click Create button, and then URL or File or Clipboard, depending on the source.
2. Paste the URL of a Postman collection or the contents of the clipboard or select a file, depending on the source too, [just as in .1 above]
3. Click import action button
4. The error appears with nothing imported

### Is there an existing issue for this?

- [x] I have searched the [issue tracker](https://www.github.com/Kong/insomnia/issues) for this problem.

### Additional Information

There's a closed issue for this, but that one pertains to swagger and has been resolved.

### Insomnia Version

2023.1.0-beta.1

### What operating system are you using?

macOS

### Operating System Version

13.0.1 (Ventura)

### Installation method

Downloaded file

### Last Known Working Insomnia version

_No response_

Reproduce the failure using a Postman collection URL, clipboard export, or selected file as described, and inspect how the import flow reports “No importers found for file.” Compare the current Postman export structure with what the importer accepts; done means the collection imports successfully instead of showing the invalid-specification error.

Written by the indexing model from the issue text.