Update humanmade/tachyon-plugin requirement from ~0.11.8 to ~0.11.9

Updates the requirements on [humanmade/tachyon-plugin](https://github.com/humanmade/tachyon-plugin) to permit the latest version.
- [Release notes](https://github.com/humanmade/tachyon-plugin/releases)
- [Commits](humanmade/tachyon-plugin@0.11.8...0.11.9)

---
updated-dependencies:
- dependency-name: humanmade/tachyon-plugin
  dependency-type: direct:production
...

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

composer.json

@@ -12,7 +12,7 @@
 	"require": {
 		"php": ">=7.1",
 		"darylldoyle/safe-svg": "2.0.3",
-		"humanmade/tachyon-plugin": "~0.11.8",
+		"humanmade/tachyon-plugin": "~0.11.9",
 		"humanmade/smart-media": "~0.5.4",
 		"humanmade/aws-rekognition": "~0.1.8",
 		"humanmade/rename-images-command": "^0.1.0",