.github: Update issue templates

Recently the issue labels were updated. The templates need to be updated
to auto-set labels correctly.

https://github.com/containers/toolbox/pull/711

.github/ISSUE_TEMPLATE/bug-report.md

@@ -2,7 +2,7 @@
 name: Bug report
 about: Toolbox's bug report template
 title: ''
-labels: bug
+labels: 1. Bug
 assignees: ''
 
 ---

.github/ISSUE_TEMPLATE/feature-request.md

@@ -2,7 +2,7 @@
 name: Feature request
 about: Toolbox's feature request template
 title: ''
-labels: feature request
+labels: 1. Feature request
 assignees: ''
 
 ---