Infinite scroll query_args does not respect "tag"

### Impacted plugin

Jetpack

### Steps to Reproduce

1. Enable infinite scroll module on Jetpack
2. Modify the `infiniteScroll.settings.query_args.tag` via JS or PHP function e.g. `infiniteScroll.settings.query_args.tag = 'tag'`
3. Test infinite scroll; the tag setting is not applied and it loads all posts regardless of tag.

### A clear and concise description of what you expected to happen.

This should filter posts by tag per the query_args settings.

### What actually happened

The tag setting is ignored and posts load without applying that filter.

### Other information

When I view the XHR request in the console, I can see that my setting is being applied in the request, but the response does not apply the setting.


However, applying the same method described above to change the 'category' query_args works as expected.

### Operating System

macOS

### OS Version

_No response_

### Browser

Chrome/Chromium, Firefox, Safari

### Browser Version(s)

_No response_

Start at the infiniteScroll.settings.query_args.tag setting and inspect the XHR request and response path, comparing it with the working category query_args behavior. Reproduce the issue with a tag value, then verify that infinite scroll loads only posts matching that tag.

Written by the indexing model from the issue text.