Bump @actions/core from 1.0.0 to 1.2.6

Bumps [@actions/core](https://github.com/actions/toolkit/tree/HEAD/packages/core) from 1.0.0 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>

package.json

@@ -21,7 +21,7 @@
   "author": "GitHub",
   "license": "MIT",
   "dependencies": {
-    "@actions/core": "^1.0.0",
+    "@actions/core": "^1.2.6",
     "@actions/exec": "^1.0.0",
     "@actions/github": "^2.2.0"
   },