Update pantheon-systems/wp-redis requirement from 1.4.6 to 1.4.7

Updates the requirements on [pantheon-systems/wp-redis](https://github.com/pantheon-systems/wp-redis) to permit the latest version.
- [Release notes](https://github.com/pantheon-systems/wp-redis/releases)
- [Commits](pantheon-systems/wp-redis@1.4.6...1.4.7)

---
updated-dependencies:
- dependency-name: pantheon-systems/wp-redis
  dependency-version: 1.4.7
  dependency-type: direct:production
...

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

Author: dependabot[bot]

composer.json

@@ -33,7 +33,7 @@
 		"humanmade/aws-xray": "~1.3.9",
 		"humanmade/s3-uploads": "^3.0.11",
 		"humanmade/cavalcade": "^2.0.2",
-		"pantheon-systems/wp-redis": "1.4.6",
+		"pantheon-systems/wp-redis": "1.4.7",
 		"humanmade/wordpress-pecl-memcached-object-cache": "2.1.0",
 		"humanmade/batcache": "~1.5.2",
 		"humanmade/ludicrousdb": "~5.0.7",