Metamaskbot uploaded links for Beta and Flask builds are broken

### Describe the bug

**Problem**: If I try to download the Flask or Beta builds for Chrome/FF/Opera published by `metamaskbot,` I land into a "Not found" page.


### Steps to reproduce

1. Open a PR with a metamaskbot build: [this one](https://github.com/MetaMask/metamask-extension/pull/16591#issuecomment-1320515112)
2. Click on `Builds ready` dropdown
3. Click any of the Beta or Flask builds -- see how you land into "Not found" page


### Error messages or log output

_No response_

### Version

n/a

### Build type

_No response_

### Browser

Chrome, Firefox

### Operating system

Windows, MacOS, Linux

### Hardware wallet

_No response_

### Additional context

_No response_

Start by reproducing the failure from PR 16591: open the “Builds ready” dropdown and test the Beta and Flask links for Chrome, Firefox, and Opera. Trace where metamaskbot generates or publishes those build links; done means each affected link reaches a downloadable build instead of a “Not found” page.

Written by the indexing model from the issue text.