[update-checkout] remove duplicate aliases

Author: shahmishal

utils/update-checkout-config.json

@@ -206,25 +206,6 @@
                 "swift-xcode-playground-support": "master",
                 "ninja": "release"
             }
-        },
-        "master-llvm-swift5-transition" : {
-            "aliases": ["master-llvm-swift5-transition","llvm-swift5-transition"],
-            "repos": {
-                "llvm": "swift-5.0-branch",
-                "clang": "swift-5.0-branch",
-                "swift": "master-llvm-swift5-transition",
-                "lldb": "llvm-swift5-transition",
-                "cmark": "master",
-                "llbuild": "master",
-                "swiftpm": "master",
-                "compiler-rt": "swift-5.0-branch",
-                "swift-corelibs-xctest": "master",
-                "swift-corelibs-foundation": "master",
-                "swift-corelibs-libdispatch": "master",
-                "swift-integration-tests": "master",
-                "swift-xcode-playground-support": "master",
-                "ninja": "release"
-            }
         }
     }
 }