Add missing globals devDependency after eslint 10 bump (PR #3689)

eslint 9.x pulled in globals@14.0.0 transitively via @eslint/eslintrc
(its legacy .eslintrc compatibility shim), which npm hoisted to the
root node_modules/globals. eslint.config.mjs imports 'globals' directly
but never declared it as a dependency, relying on that hoisting.

eslint 10 drops @eslint/eslintrc, so globals is no longer pulled in at
the root (only nested under eslint-plugin-n for its own use), and
`npm run eslint` fails with ERR_MODULE_NOT_FOUND for 'globals'. This
matches the "lint" job failures on PR #3689's dependabot build-group
bump (esbuild 0.28.1->0.28.2, eslint 9.39.4->10.11.0, sass
1.102.0->1.104.1).

Declaring globals explicitly as a devDependency fixes eslint.config.mjs
resolution; verified `npm run lint` (eslint, prettier, tsc,
check-lockfile) and `npm run test.node` pass locally with this change.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_019cuRycMWwzr7smwxqgNpM9

Author: claude

package-lock.json

@@ -52,6 +52,7 @@
         "eslint": "^10.11.0",
         "fake-indexeddb": "^6.0.0",
         "firefox-webext-playwright-harness": "github:duckduckgo/firefox-webext-playwright-harness#0.3.0",
+        "globals": "^17.12.0",
         "jasmine": "^5.9.0",
         "jsdom": "^26.0.0",
         "karma": "6.4.4",