macos-13 image used in workflows is depracted

Workflows give warning: 
```
The macOS-13 based runner images are being deprecated, consider switching to macOS-15 (macos-15-intel) 
or macOS 15 arm64 (macos-latest) instead. 
For more details see https://github.com/actions/runner-images/issues/13046
```
Should either upgrade or remove support for intel macs.