Agent skills scripts executed in wrong folder

### Describe the bug

If I create a skill that should execute a the script `scripts/myscript.sh`, I should be able to reference it in SKILLS.md with:
Run the script: `scripts/myscript.sh`
according to official spec: https://agentskills.io/specification#file-references

However, if I do that in copilot-cli or VS Code with Copilot Github, it tries to execute the script from my root, not my skills folder, so it can't find the script.

I can solve it by changing it to:
Run the script: `./scripts/myscript.sh` (with a leading dot)
Which makes copilot-cli and VS Code run it correctly. However that breaks Claude Code, which then tries to execute it from the root instead.

As the official spec shows the examples not using a leading dot, I believe you should adjust accordingly.

PS: As a workaround to get it working in both agents I can use the full path instead, but that's just ugly and not recommended.

### Affected version

_No response_

### Steps to reproduce the behavior

_No response_

### Expected behavior

_No response_

### Additional context

_No response_