Breaking: #77591 - Removed WorkspaceService->isOldStyleWorkspaceUsed¶
WorkspaceService->isOldStyleWorkspaceUsed() was removed without substitution. It existed to identify if
Workspaces still were configured for TYPO3 4.4.
Calling the PHP method directly will result in a fatal PHP error.
TYPO3 installations using workspaces and extending the workspaces functionality extensively by providing a fallback layer to functionality for TYPO3 4.4 or lower.
Remove any occurrences to the PHP method.