GIT_SILENT: Remove .arcconfig and .arclint

KDE has switched to GitLab.

src/wayland/.arcconfig

-{
-  "phabricator.uri" : "https://phabricator.kde.org/"
-}
-

src/wayland/.arclint

-{
-  "exclude": "(^test/)",
-  "linters": {
-    "spelling": {
-      "type": "spelling"
-    },
-    "merge-conflict": {
-      "type": "merge-conflict"
-    },
-    "xml": {
-      "type": "xml",
-      "include": "(\\.xml$)"
-    }
-  }
-}