Update deploy.yml to remove set output

Author: timkim

.github/workflows/deploy.yml

@@ -39,7 +39,7 @@ jobs:
           result-encoding: string
       - name: Get branch name
         shell: bash
-        run: echo "##[set-output name=branch;]${GITHUB_REF#refs/heads/}"
+        run: echo "##[name=branch;]${GITHUB_REF#refs/heads/} >> GITHUB_OUTPUT"
         id: get_branch
 
   echo-state: