fix: add @actions/core as dependency (#450)

`@actions/core` is used in the GitHub logger transport despite not actually
being installed directly, meaning it's only available when `@reporters/github`
is downloaded w/ dev dependencies. In Node core we don't install dev
dependencies causing this to throw.

Signed-off-by: flakey5 <[email protected]>

Author: flakey5

package-lock.json

@@ -39,6 +39,7 @@
     "prettier": "3.6.2"
   },
   "dependencies": {
+    "@actions/core": "^1.11.1",
     "@clack/prompts": "^0.11.0",
     "@heroicons/react": "^2.2.0",
     "@minify-html/node": "^0.16.4",