ebpf-verifier is cloned twice

### Describe the bug

We have
* external\ebpf-verifier
* external\ubpf\external\ebpf-verifier

This just consumes extra disk space and time/bandwidth to clone and update. It would be more efficient to only clone one copy.
We could either:
1) Remove external\ebpf-verifier and just use the one under ubpf. The disadvantage is that we couldn't update the verifier until ubpf is updated. Or,
2) Do a [shallow clone](https://stackoverflow.com/questions/2144406/how-to-make-shallow-git-submodules) of ubpf.

### OS information

_No response_

### Steps taken to reproduce bug

Clone the repository recursively
dir /s ebpf-verifier

### Expected behavior

Only one copy present

### Actual outcome

Two copies present

### Additional details

_No response_