Remove older versions from the docs (#11383)

To reduce Algolia operations and indexes older versions get removed

Author: SenseException

.doctrine-project.json

@@ -94,42 +94,6 @@
             "branchName": "2.10.x",
             "slug": "2.10",
             "maintained": false
-        },
-        {
-            "name": "2.9",
-            "branchName": "2.9.x",
-            "slug": "2.9",
-            "maintained": false
-        },
-        {
-            "name": "2.8",
-            "branchName": "2.8.x",
-            "slug": "2.8",
-            "maintained": false
-        },
-        {
-            "name": "2.7",
-            "branchName": "2.7",
-            "slug": "2.7",
-            "maintained": false
-        },
-        {
-            "name": "2.6",
-            "branchName": "2.6",
-            "slug": "2.6",
-            "maintained": false
-        },
-        {
-            "name": "2.5",
-            "branchName": "2.5",
-            "slug": "2.5",
-            "maintained": false
-        },
-        {
-            "name": "2.4",
-            "branchName": "2.4",
-            "slug": "2.4",
-            "maintained": false
         }
     ]
 }