Switch to node action

This is done to be able to pass loaded secrets as output. This is not available with a composite action, unless we hard-code the action's outputs, which is not a desired outcome.

action.yml

@@ -9,9 +9,5 @@ inputs:
     description: Whether to unset environment variables populated by 1Password in earlier job steps
     default: false
 runs:
-  using: composite
-  steps: 
-    - run: |
-        export INPUT_UNSET_PREVIOUS=${{ inputs.unset-previous }}
-        ${{ github.action_path }}/entrypoint.sh
-      shell: bash
+  using: 'node12'
+  main: 'dist/index.js'