Update dependency @actions/core to v1.2.4

Author: renovate-bot

package-lock.json

@@ -23,7 +23,7 @@
   },
   "homepage": "https://github.com/peter-evans/create-issue-from-file",
   "dependencies": {
-    "@actions/core": "1.2.0",
+    "@actions/core": "1.2.4",
     "@actions/exec": "1.0.2",
     "@actions/tool-cache": "1.1.2",
     "is-docker": "2.0.0"