docs: fix typo in showCircularDependencies deprecation message

(cherry picked from commit 5f61556)

Author: alan-agius4

packages/angular_devkit/build_angular/src/browser/schema.json

@@ -276,7 +276,7 @@
       "type": "boolean",
       "description": "Show circular dependency warnings on builds.",
       "default": false,
-      "x-deprecated": "The recommended method to detect circular dependencies in project code is to use a either a lint rule or other external tooling."
+      "x-deprecated": "The recommended method to detect circular dependencies in project code is to use either a lint rule or other external tooling."
     },
     "buildOptimizer": {
       "type": "boolean",

packages/angular_devkit/build_angular/src/server/schema.json

@@ -174,7 +174,7 @@
       "type": "boolean",
       "description": "Show circular dependency warnings on builds.",
       "default": false,
-      "x-deprecated": "The recommended method to detect circular dependencies in project code is to use a either a lint rule or other external tooling."
+      "x-deprecated": "The recommended method to detect circular dependencies in project code is to use either a lint rule or other external tooling."
     },
     "namedChunks": {
       "type": "boolean",