Update nesbot/carbon requirement from ^2.66 to ^3.8

Updates the requirements on [nesbot/carbon](https://github.com/briannesbitt/Carbon) to permit the latest version.
- [Release notes](https://github.com/briannesbitt/Carbon/releases)
- [Commits](briannesbitt/Carbon@2.66.0...3.8.0)

---
updated-dependencies:
- dependency-name: nesbot/carbon
  dependency-type: direct:production
...

Signed-off-by: dependabot[bot] <support@github.com>

composer.json

@@ -27,7 +27,7 @@
     "ext-simplexml": "*",
     "ext-libxml": "*",
     "ext-fileinfo": "*",
-    "nesbot/carbon": "^2.66",
+    "nesbot/carbon": "^3.8",
     "guzzlehttp/guzzle": "^6.5 || ^7.2",
     "ezyang/htmlpurifier": "^4.14"
   },