Update ghost

Changes:

- https://github.com/docker-library/ghost/commit/f04a5ba: Update to 4.8.0, ghost-cli 1.17.3

library/ghost

@@ -4,14 +4,14 @@ Maintainers: Tianon Gravi <[email protected]> (@tianon),
              Joseph Ferguson <[email protected]> (@yosifkit)
 GitRepo: https://github.com/docker-library/ghost.git
 
-Tags: 4.7.0, 4.7, 4, latest
+Tags: 4.8.0, 4.8, 4, latest
 Architectures: amd64, arm32v7, arm64v8, ppc64le, s390x
-GitCommit: f49e97d38c98b8b3838b9ac04ca6c280703e7c49
+GitCommit: f04a5ba58c12aaf8d09c8c8e14e9aa90a0315293
 Directory: 4/debian
 
-Tags: 4.7.0-alpine, 4.7-alpine, 4-alpine, alpine
+Tags: 4.8.0-alpine, 4.8-alpine, 4-alpine, alpine
 Architectures: amd64, arm32v6, arm32v7, arm64v8
-GitCommit: f49e97d38c98b8b3838b9ac04ca6c280703e7c49
+GitCommit: f04a5ba58c12aaf8d09c8c8e14e9aa90a0315293
 Directory: 4/alpine
 
 Tags: 3.42.5, 3.42, 3