chore(workflow): remove duplicated issue label (#4206)

Author: chenjiahan

.github/ISSUE_TEMPLATE/bug-report.en-US.yml

@@ -2,7 +2,6 @@ name: '🐞 Bug Report'
 description: Report a Bug to Rsbuild
 title: '[Bug]: '
 type: Bug
-labels: ['🐞 bug']
 body:
   - type: markdown
     attributes:

.github/ISSUE_TEMPLATE/feature-request.en-US.yml

@@ -2,7 +2,6 @@ name: '💡 Feature Request'
 description: Submit a new feature request to Rsbuild
 title: '[Feature]: '
 type: Enhancement
-labels: ['💡 feature']
 body:
   - type: markdown
     attributes: