Add RISC-V (riscv64) Support to OpenTelemetry Collector Releases

[shanduur]

I'd like to request official OpenTelemetry Collector images for RISC-V (riscv64) architecture. Currently, I see images released for linux, windows, and darwin operating systems across 386, amd64, arm64, ppc64le, arm, and s390x architectures. The RISC-V ecosystem is rapidly growing in areas like embedded systems, edge computing, and cloud infrastructure. Providing official support means more users can easily deploy the collector without needing to build from source. This move would future-proof the OpenTelemetry Collector as RISC-V adoption continues to expand. I'm happy to help in any way I can during the implementation of this feature.