fix: rule.issuerLayer

[SyMind]

Summary

Fix isserLayer and issuer match wrong when layer and issuer of target dependency are empty.

Checklist

• Tests updated (or not required).
• Documentation updated (or not required).

[netlify]

✅ Deploy Preview for rspack canceled.

Name	Link
🔨 Latest commit	4c57b12
🔍 Latest deploy log	https://app.netlify.com/sites/rspack/deploys/67494326a1ee310008b780d0

[codspeed-hq]

CodSpeed Performance Report

Merging #8572 will not alter performance

_{Comparing rule.issuerLayer (4c57b12) with main (5f77de0)}

Summary

✅ 1 untouched benchmarks

[chenjiahan]

I suggest the PR title can be more specific.