function deRegisterNavigationFilter(oModel) {
		const oShellNavigationInternalService = oModel.getUShellService("ShellNavigationInternal");
		if (oShellNavigationInternalService) {
			oShellNavigationInternalService.unregisterNavigationFilter(_mVariantIdChangeHandlers[oModel.sFlexReference]);
			delete _mVariantIdChangeHandlers[oModel.sFlexReference];
		}
	}
De-registers navigation filter function for the ushell ShellNavigationInternal service.

@param {sap.ui.fl.variants.VariantModel} oModel - Variant Model

@private