fix: remove environment placeholder and make blocking field optional in bug report template

Author: Copilot

.github/ISSUE_TEMPLATE/bug-report.yml

@@ -39,10 +39,6 @@ body:
     attributes:
       label: Environment details
       description: "OS, Node.js version, shell, and any other relevant info."
-      placeholder: |
-        - OS: Windows 11
-        - Node.js: 20.11.0
-        - Shell: PowerShell 7.4
     validations:
       required: true
 
@@ -67,4 +63,4 @@ body:
         - "Yes"
         - "No"
     validations:
-      required: true
+      required: false