meta: remove automatic bug label on bug reports

People sometimes use the bug report template for things that are support.
Maintainers will confirm whether it's a bug with the appropriate label.

.github/ISSUE_TEMPLATE/bug_report.md

@@ -1,7 +1,6 @@
 ---
 name: Bug report
 about: Create a report to help us improve
-labels: 'Type: bug'
 
 ---