Bump @actions/core from 1.2.6 to 1.9.1

Bumps [@actions/core](https://github.com/actions/toolkit/tree/HEAD/packages/core) from 1.2.6 to 1.9.1.
- [Release notes](https://github.com/actions/toolkit/releases)
- [Changelog](https://github.com/actions/toolkit/blob/main/packages/core/RELEASES.md)
- [Commits](https://github.com/actions/toolkit/commits/HEAD/packages/core)

---
updated-dependencies:
- dependency-name: "@actions/core"
  dependency-type: direct:development
...

Signed-off-by: dependabot[bot] <support@github.com>

package.json

@@ -7,7 +7,7 @@
     "author": "webfactory GmbH <info@webfactory.de>",
     "license": "MIT",
     "devDependencies": {
-        "@actions/core": "^1.2.4",
+        "@actions/core": "^1.9.1",
         "@zeit/ncc": "^0.20.5"
     },
     "scripts": {