Update humanmade/asset-loader requirement from ^0.6.3 to ^0.6.4

Updates the requirements on [humanmade/asset-loader](https://github.com/humanmade/asset-loader) to permit the latest version.
- [Release notes](https://github.com/humanmade/asset-loader/releases)
- [Changelog](https://github.com/humanmade/asset-loader/blob/main/CHANGELOG.md)
- [Commits](humanmade/asset-loader@v0.6.3...v0.6.4)

---
updated-dependencies:
- dependency-name: humanmade/asset-loader
  dependency-type: direct:production
...

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

composer.json

@@ -16,7 +16,7 @@
     "altis/cms-installer": "^0.4.4",
     "humanmade/clean-html": "^2.0.0",
     "humanmade/altis-reusable-blocks": "~0.2.4",
-    "humanmade/asset-loader": "^0.6.3",
+    "humanmade/asset-loader": "^0.6.4",
     "10up/simple-local-avatars": "~2.7.7"
   },
   "autoload": {