[Security] Bump @actions/core from 1.2.3 to 1.2.6

Bumps [@actions/core](https://github.com/actions/toolkit/tree/HEAD/packages/core) from 1.2.3 to 1.2.6. **This update includes a security fix.**
- [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-preview[bot] <support@dependabot.com>

package.json

@@ -33,7 +33,7 @@
     },
     "dependencies": {
         "@actions-rs/core": "^0.0.9",
-        "@actions/core": "^1.2.3",
+        "@actions/core": "^1.2.6",
         "@actions/exec": "^1.0.3",
         "@actions/io": "^1.0.2"
     },