Bump github.com/apple/swift-docc-plugin from 1.4.1 to 1.4.2 (#65)

Bumps [github.com/apple/swift-docc-plugin](https://github.com/apple/swift-docc-plugin) from 1.4.1 to 1.4.2.
- [Release notes](https://github.com/apple/swift-docc-plugin/releases)
- [Commits](swiftlang/swift-docc-plugin@1.4.1...1.4.2)

---
updated-dependencies:
- dependency-name: github.com/apple/swift-docc-plugin
  dependency-type: direct:production
  update-type: version-update:semver-patch
...

Signed-off-by: dependabot[bot] <[email protected]>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

Package.resolved

@@ -32,8 +32,8 @@
       "kind" : "remoteSourceControl",
       "location" : "https://github.com/apple/swift-docc-plugin",
       "state" : {
-        "revision" : "0510d9160330025fb5823f7845c26af3cd56a405",
-        "version" : "1.4.1"
+        "revision" : "2eb22993b3dfd0c0d32729b357c8dabb6cd44680",
+        "version" : "1.4.2"
       }
     },
     {