Add support for RISC-V 64

[shanduur]

Adding support for RISC-V (GOARCH=riscv64) in the Kine project is a strategic decision that aligns with the growing demand for efficient, low-power hardware at the edge and in embedded environments. Kine's lightweight architecture offers a compelling alternative to traditional data storage systems like ETCD, which can be overkill for resource-constrained devices common in edge and embedded deployments. RISC-V is rapidly becoming a popular architecture due to its open-source nature and potential for customization to suit various application needs. By supporting GOARCH=riscv64, Kine can extend its lightweight, scalable, and low-resource storage capabilities to a broader range of hardware platforms, thus making it a more viable choice for developers working with RISC-V at the edge and in embedded contexts. This move not only expands Kine's applicability but also facilitates the development of innovative solutions on RISC-V-based systems, supporting the overall ecosystem's growth.