fix: add the output to the job

Author: mattmalec

.github/workflows/release.yml

@@ -6,9 +6,12 @@ on:
 jobs:
   branch_exists:
     runs-on: ubuntu-20.04
+    outputs:
+      branch_exists: ${{ steps.check_branch.outputs.branch_exists }}
     steps:
       - uses: actions/checkout@v2
       - name: Check if release already exists
+        id: check_branch
         env:
           REF: ${{ github.ref }}
         run: |