Update ghost

Changes:

- https://github.com/docker-library/ghost/commit/3a62cb8: Update to 4.2.1, ghost-cli 1.16.3

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: 4.2.0, 4.2, 4, latest
+Tags: 4.2.1, 4.2, 4, latest
 Architectures: amd64, arm32v7, arm64v8, ppc64le, s390x
-GitCommit: c88277bcc3a8df36d451b0e862563f2d04d462d8
+GitCommit: 3a62cb8161edc9da1ab40c93a2242a779093c58e
 Directory: 4/debian
 
-Tags: 4.2.0-alpine, 4.2-alpine, 4-alpine, alpine
+Tags: 4.2.1-alpine, 4.2-alpine, 4-alpine, alpine
 Architectures: amd64, arm32v6, arm32v7, arm64v8
-GitCommit: c88277bcc3a8df36d451b0e862563f2d04d462d8
+GitCommit: 3a62cb8161edc9da1ab40c93a2242a779093c58e
 Directory: 4/alpine
 
 Tags: 3.42.4, 3.42, 3