Merge pull request #600 from Iblis/textmeshpro_unity6_adoptions

TextMeshPro Unity6 adoptions

Author: neuecc

src/UniTask/Assets/Plugins/UniTask/Runtime/External/TextMeshPro/UniTask.TextMeshPro.asmdef

@@ -16,7 +16,12 @@
             "name": "com.unity.textmeshpro",
             "expression": "",
             "define": "UNITASK_TEXTMESHPRO_SUPPORT"
+        },
+        {
+            "name": "com.unity.ugui",
+            "expression": "2.0.0",
+            "define": "UNITASK_TEXTMESHPRO_SUPPORT"
         }
     ],
     "noEngineReferences": false
-}
+}