issue template: strip title prefix

Author: Mic92

.github/ISSUE_TEMPLATE/bug_report.yml

@@ -1,6 +1,5 @@
 name: Bug Report
 description: File a bug report to help us improve nixos-anywhere
-title: "[Bug]: "
 labels: ["bug"]
 body:
   - type: markdown

.github/ISSUE_TEMPLATE/feature_request.yml

@@ -1,7 +1,6 @@
 name: Feature Request
 description: Suggest an idea or enhancement for nixos-anywhere
-title: "[Feature]: "
-labels: ["enhancement"]
+labels: ["feature"]
 body:
   - type: markdown
     attributes: