Bump ts-loader in /samples/web-extension/typescript

Bumps [ts-loader](https://github.com/TypeStrong/ts-loader) from 8.0.17 to 8.0.18.
- [Release notes](https://github.com/TypeStrong/ts-loader/releases)
- [Changelog](https://github.com/TypeStrong/ts-loader/blob/master/CHANGELOG.md)
- [Commits](TypeStrong/ts-loader@v8.0.17...v8.0.18)

Signed-off-by: dependabot[bot] <[email protected]>

Author: dependabot[bot]

samples/web-extension/typescript/package-lock.json

@@ -14,7 +14,7 @@
     "webextension-polyfill": "^0.7.0"
   },
   "devDependencies": {
-    "ts-loader": "^8.0.17",
+    "ts-loader": "^8.0.18",
     "typescript": "^4.1.5",
     "web-ext-types": "^3.2.1",
     "webpack": "^5.26.3",