Remove a bash task from webgpu CI pipeline (#19682)
### Description
It is a "Bash" task that requires running bash on Windows. Most Windows
operating systems do not have Bash installed. Given this task is only
debugging purposes, we can remove it for now.
### Motivation and Context
I am making this change because I am regenerating the VM image in a
different manner, and the new image does not contain bash. Once this PR
is in, I can switch the images.
