Bump cross-fetch and @ampproject/toolbox-optimizer (google#151)

Bumps [cross-fetch](https://github.com/lquixada/cross-fetch) to 3.1.5 and updates ancestor dependency [@ampproject/toolbox-optimizer](https://github.com/ampproject/amp-toolbox/tree/HEAD/packages/optimizer). These dependencies need to be updated together.


Updates `cross-fetch` from 3.1.2 to 3.1.5
- [Release notes](https://github.com/lquixada/cross-fetch/releases)
- [Commits](lquixada/cross-fetch@v3.1.2...v3.1.5)

Updates `@ampproject/toolbox-optimizer` from 2.8.7 to 2.9.0
- [Release notes](https://github.com/ampproject/amp-toolbox/releases)
- [Changelog](https://github.com/ampproject/amp-toolbox/blob/main/CHANGELOG.md)
- [Commits](https://github.com/ampproject/amp-toolbox/commits/v2.9.0/packages/optimizer)

---
updated-dependencies:
- dependency-name: cross-fetch
  dependency-type: indirect
- dependency-name: "@ampproject/toolbox-optimizer"
  dependency-type: direct:production
...

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

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

package.json

@@ -46,7 +46,7 @@
     "shorthash": "0.0.2"
   },
   "dependencies": {
-    "@ampproject/toolbox-optimizer": "^2.8.3",
+    "@ampproject/toolbox-optimizer": "^2.9.0",
     "any-shell-escape": "^0.1.1",
     "clean-css": "^4.2.3",
     "concurrently": "^7.0.0",