ci: update matrix action to v3.0 (#1525)

**Issue number:** N/A

### PR Type

**What kind of change does this PR introduce?**
* [ ] Feature
* [ ] Bug Fix
* [ ] Refactoring (no functional or API changes)
* [ ] Documentation Update
* [x] Maintenance (dependency updates, CI, etc.)

## Summary

### Changes

Using latest matrix action that does not require `.addonmatrix` file in
the root so cleaned up this file as well.

### User experience

N/A

## Checklist

If an item doesn't apply to your changes, leave it unchecked.

* [x] I have performed a self-review of this change according to the
[development
guidelines](https://splunk.github.io/addonfactory-ucc-generator/contributing/#development-guidelines)
* [ ] Tests have been added/modified to cover the changes [(testing
doc)](https://splunk.github.io/addonfactory-ucc-generator/contributing/#build-and-test)
* [ ] Changes are documented
* [x] PR title and description follows the [contributing
principles](https://splunk.github.io/addonfactory-ucc-generator/contributing/#pull-requests)

.github/workflows/build-test-release.yml

@@ -22,7 +22,7 @@ jobs:
     steps:
       - uses: actions/checkout@v4
       - id: matrix
-        uses: splunk/addonfactory-test-matrix-action@v2.1
+        uses: splunk/addonfactory-test-matrix-action@v3.0
 
   fossa-scan:
     continue-on-error: true