Remove Beta label from bug issue template (opensearch-project#169)

Signed-off-by: Tyler Ohlsen <ohltyler@amazon.com>

Author: ohltyler

.github/ISSUE_TEMPLATE/bug_template.md

@@ -2,7 +2,7 @@
 name: 🐛 Bug report
 about: Create a report to help us improve
 title: '[BUG]'
-labels: 'bug, untriaged, Beta'
+labels: 'bug, untriaged'
 assignees: ''
 ---