Deliverables within a classical SLDC are not simple parts of the product or the alpha-version of it, but key communication tools between gateways that support the understanding across the people and the stages which are part in a project.
UX Deliverables are back al though Lean UX methods are an amazingly helpful approach for creating, for ideation, and getting solutions into reality. However, since every design is nothing but an hypothesis, they need to be described to understand every design decision, every assumption, and every detail that could be out of the scope of the proposal.
It is true
you don’t solve problems with design documentation
however documents are your point of iteration, your tool for expressing ideas, and the way to move forward your project during the time and the involved stakeholders.
Do not feel overwhelmed by the design deliverables, just use it in favor of the process without killing the agile flow of creativity and execution.