chore: update issue template labels for consistency

.github/ISSUE_TEMPLATE/bug.yml

@@ -1,7 +1,7 @@
 name: "👾 报告 bug"
 description: "报告 bug"
 labels:
-  - ":space_invader: Bug"
+  - "bug"
 assignees:
   - krau
 body:

.github/ISSUE_TEMPLATE/feature.yml

@@ -1,7 +1,7 @@
 name: "⭐️ 功能请求"
 description: "功能请求"
 labels:
-  - ":fire: Enhancement"
+  - "enhancement"
 assignees:
   - krau
 body: