fix: double-set outputs to avoid issues

`actions-toolkit` should do that already, but I feel like this is hte easiest way to fix the issue.
Ref #189

src/util.ts

@@ -117,4 +117,5 @@ export function readJSON(filePath: string) {
 export function setOutput(name: Output, value: 'true' | 'false') {
   core.debug(`Setting output: ${name}=${value}`)
   tools.outputs[name] = value
+  core.setOutput(name, value)
 }