manjaro/manjaro-iso-action/main/action.yml (Line: 358, Col: 12): Unexpected symbol: '@'. Located at position 43 within expression: steps.upload-prepare.outputs.upload-files[@]

GitHub.DistributedTask.ObjectTemplating.TemplateValidationException: The template is not valid. manjaro/manjaro-iso-action/main/action.yml (Line: 358, Col: 12): Unexpected symbol: '@'. Located at position 43 within expression: steps.upload-prepare.outputs.upload-files[@] at GitHub.DistributedTask.ObjectTemplating.TemplateValidationErrors.Check() at GitHub.Runner.Worker.ActionManifestManager.ConvertRuns(IExecutionContext executionContext, TemplateContext templateContext, TemplateToken inputsToken, String fileRelativePath, MappingToken outputs) at GitHub.Runner.Worker.ActionManifestManager.Load(IExecutionContext executionContext, String manifestFile)