build(deps): bump @actions/core in /.github/actions/send-tweet (firebase#1052)

Bumps [@actions/core](https://github.com/actions/toolkit/tree/HEAD/packages/core) from 1.2.2 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] <[email protected]>

Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

Author: dependabot[bot]

.github/actions/send-tweet/package-lock.json

@@ -14,7 +14,7 @@
   "author": "Firebase <[email protected]> (https://firebase.google.com/)",
   "license": "Apache-2.0",
   "dependencies": {
-    "@actions/core": "^1.2.2",
+    "@actions/core": "^1.2.6",
     "twitter": "^1.7.1"
   },
   "devDependencies": {