[Chore] Remove unmaintained version in issue template (#17870)

Author: SbloodyS

.github/ISSUE_TEMPLATE/bug-report.yml

@@ -99,8 +99,6 @@ body:
         Which version of Apache DolphinScheduler are you running? We only accept bugs report from the LTS projects.
       options:
         - dev
-        - 3.1.x
-        - 3.2.x
         - 3.3.0-alpha
         - 3.3.1
         - 3.3.2