Update package dependency

Package.resolved

@@ -1,16 +0,0 @@
-{
-  "object": {
-    "pins": [
-      {
-        "package": "SwiftDocCPlugin",
-        "repositoryURL": "https://github.com/apple/swift-docc-plugin",
-        "state": {
-          "branch": null,
-          "revision": "3303b164430d9a7055ba484c8ead67a52f7b74f6",
-          "version": "1.0.0"
-        }
-      }
-    ]
-  },
-  "version": 1
-}

Package.swift

@@ -13,11 +13,4 @@ let package = Package(
             path: "Sources"
         )
     ]
-)
-
-#if swift(>=5.6)
-  // Add the documentation compiler plugin if possible
-  package.dependencies.append(
-    .package(url: "https://github.com/apple/swift-docc-plugin", from: "1.0.0")
-  )
-#endif
+)