TASK: Remove Neos.Node.inBackend() and Neos.Node.isLive() eel helper

It was deprecated in #4505 in favor of `${userInterfaceMode.isEdit}`.
Since the ui is adjusted in neos/neos-ui#3618 it can now be removed.

Neos.Neos/Classes/Fusion/Helper/NodeHelper.php

@@ -95,18 +95,6 @@ public function labelForNode(Node $node): NodeLabelToken
         return new NodeLabelToken($node);
     }
 
-    /**
-     * @param Node $node
-     * @return bool
-     * @deprecated Remove before Neos 9.0 !!! Use ${userInterfaceMode.isEdit || userInterfaceMode.isPreview} instead
-     */
-    public function inBackend(Node $node): bool
-    {
-        $contentRepository = $this->contentRepositoryRegistry->get($node->subgraphIdentity->contentRepositoryId);
-        $nodeAddressFactory = NodeAddressFactory::create($contentRepository);
-        return !$nodeAddressFactory->createFromNode($node)->isInLiveWorkspace();
-    }
-
     /**
      * @param Node $node
      * @return int
@@ -132,13 +120,6 @@ public function path(Node $node): string
         return AbsoluteNodePath::fromLeafNodeAndAncestors($node, $ancestors)->serializeToString();
     }
 
-    public function isLive(Node $node): bool
-    {
-        $contentRepository = $this->contentRepositoryRegistry->get($node->subgraphIdentity->contentRepositoryId);
-        $nodeAddressFactory = NodeAddressFactory::create($contentRepository);
-        return $nodeAddressFactory->createFromNode($node)->isInLiveWorkspace();
-    }
-
     /**
      * If this node type or any of the direct or indirect super types
      * has the given name.