chore: add liavweiss as epic owner to relevant GHAs (#550)

@liavweiss has been helping me with a lot of planning discussions and been involved with notebooks-v2 for awhile now.  it will be helpful to give him the ability to create epics/features/tasks and start to own them.

Signed-off-by: Andy Stoneberg <astonebe@redhat.com>

Author: andyatmiami

.github/workflows/slash-commands.yaml

@@ -11,7 +11,7 @@ jobs:
   handle-slash-command:
     if: |
       github.event.issue.pull_request == null
-      && contains('["thesuperzapper", "ederign", "andyatmiami", "paulovmr", "jenny-s51", "harshad16", "thaorell", "kimwnasptd"]', github.event.comment.user.login)
+      && contains('["thesuperzapper", "ederign", "andyatmiami", "paulovmr", "jenny-s51", "harshad16", "thaorell", "kimwnasptd", "liavweiss"]', github.event.comment.user.login)
       && (
           contains(github.event.comment.body, '/add-sub-issue')
           || contains(github.event.comment.body, '/remove-sub-issue')

.github/workflows/validate-planning-label.yml

@@ -5,7 +5,7 @@ on:
     types: [opened, labeled]
 
 env:
-  AUTHORIZED_USERS: '["thesuperzapper", "ederign", "andyatmiami", "paulovmr", "jenny-s51", "harshad16", "thaorell", "kimwnasptd"]'
+  AUTHORIZED_USERS: '["thesuperzapper", "ederign", "andyatmiami", "paulovmr", "jenny-s51", "harshad16", "thaorell", "kimwnasptd", "liavweiss"]'
 
 permissions:
   issues: write