Bump @actions/core from 1.1.1 to 1.2.6

Bumps [@actions/core](https://github.com/actions/toolkit/tree/HEAD/packages/core) from 1.1.1 to 1.2.6.
- [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)

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

Author: dependabot[bot]

package-lock.json

@@ -25,7 +25,7 @@
   },
   "homepage": "https://github.com/timheuer/base64-to-file#readme",
   "dependencies": {
-    "@actions/core": "^1.1.1"
+    "@actions/core": "^1.2.6"
   },
   "devDependencies": {
     "@zeit/ncc": "^0.20.5",