Update monolog/monolog requirement from ^2.9 to ^2.11

Updates the requirements on [monolog/monolog](https://github.com/Seldaek/monolog) to permit the latest version.
- [Release notes](https://github.com/Seldaek/monolog/releases)
- [Changelog](https://github.com/Seldaek/monolog/blob/2.11.0/CHANGELOG.md)
- [Commits](Seldaek/monolog@2.9.0...2.11.0)

---
updated-dependencies:
- dependency-name: monolog/monolog
  dependency-version: 2.11.0
  dependency-type: direct:production
...

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

Author: dependabot[bot]

composer.json

@@ -38,7 +38,7 @@
 		"humanmade/batcache": "~1.5.2",
 		"humanmade/ludicrousdb": "~5.0.7",
 		"humanmade/aws-ses-wp-mail": "~1.3.1",
-		"monolog/monolog": "^2.9",
+		"monolog/monolog": "^2.11",
 		"maxbanton/cwh": "^2.0"
 	},
 	"extra": {