Update issue templates

Author: infin8x

.github/ISSUE_TEMPLATE/bug-slayer.md

@@ -3,6 +3,8 @@ name: The Bug Slayer bounty submission
 about: Submit a CodeQL query for [The Bug Slayer bounty](https://securitylab.github.com/bounties)
 title: "[DATE]: [FEATURE NAME]"
 labels: The Bug Slayer
+assignees: ''
+
 ---
 
 ## Query