fix: move TraceContext.spans from class to instance attribute#4432

ashtarkb wants to merge 1 commit intollamastack:release-0.3.xllamastack/llama-stack:release-0.3.xfrom

ashtarkb:fix/tracecontext-shared-spans-bugashtarkb/llama-stack:fix/tracecontext-shared-spans-bugCopy head branch name to clipboard