Remove non-existing 8.3 version

SenseException · web-flow · commit e33739157269 · 2021-04-14T09:35:21.000+02:00
diff --git a/.doctrine-project.json b/.doctrine-project.json
@@ -10,12 +10,6 @@
             "slug": "9.0",
             "upcoming": true
         },
-        {
-            "name": "8.3",
-            "branchName": "8.3.x",
-            "slug": "8.3",
-            "upcoming": true
-        },
         {
             "name": "8.2",
             "branchName": "8.2.x",
