Replace deprecated command with environment file (#142)

Signed-off-by: jongwooo <[email protected]>

Author: jongwooo

.github/workflows/push.yml

@@ -38,7 +38,7 @@ jobs:
 
       - name: Get tag
         shell: bash
-        run: echo "##[set-output name=branch;]$(echo ${GITHUB_REF##*/})"
+        run: echo "branch=$(echo ${GITHUB_REF##*/})" >> $GITHUB_OUTPUT
         id: tag
 
       - name: Building litmusctl
@@ -55,4 +55,4 @@ jobs:
 
       - name: Copy binaries to the litmusctl s3 bucket
         run: |
-          aws s3 sync platforms-${{ steps.tag.outputs.branch }} s3://${{ secrets.AWS_S3_BUCKET }}
+          aws s3 sync platforms-${{ steps.tag.outputs.branch }} s3://${{ secrets.AWS_S3_BUCKET }}