[BUILD] Remove the hard-coded separator in tracestate #9640

Job	Run time
Bazel noexcept	12m 29s
Bazel asan config	16m 51s
Bazel nortti	12m 56s
Bazel on MacOS	11m 4s
Bazel	13m 2s
Bazel with async export	12m 50s
Bazel tsan config	13m 40s
Bazel valgrind	15m 3s
Bazel with external abseil	12m 47s
Benchmark	8m 21s
CMake test (with abseil)	4m 43s
CMake clang 18 (maintainer mode, abiv2)	8m 51s
CMake clang 18 (maintainer mode, async)	8m 24s
CMake clang 18 (maintainer mode, sync)	8m 35s
CMake do not install test (with otlp-exporter)	14m 28s
CMake gcc 14 (maintainer mode, async)	12m 18s
CMake gcc 14 (maintainer mode, sync)	12m 39s
CMake install test (with abseil)	4m 19s
CMake test (with modern protobuf,grpc and abseil)	18m 27s
CMake msvc (maintainer mode)	7m 20s
CMake msvc (maintainer mode) with C++20	8m 35s
CMake test (with opentracing-shim)	3m 55s
CMake test (build shared libraries with otlp-exporter and static gRPC)	13m 13s
CMake test (with otlp-exporter)	13m 41s
CMake test (without otlp-exporter)	4m 36s
CMake C++14 test(GCC)	4m 30s
CMake C++17 test(GCC)	4m 52s
CMake C++20 test(Clang with libc++)	8m 22s
CMake C++20 test(GCC)	8m 16s
CMake C++23 test(Clang with libc++)	8m 45s
CMake C++23 test(GCC)	8m 18s
CMake test (without otlp-exporter and with async export)	5m 2s
Code coverage	11m 27s
Copyright	4s
DocFX check	54s
Format	32s
markdown-lint	8s
misspell	3s
Plugin -> CMake	49s
shellcheck	10s
CMake -> exporter proto	12m 17s
Bazel Windows	20m 45s
Plugin -> CMake Windows	5m 45s
CMake (With async export) -> exporter proto	11m 20s
CMake -> exporter proto (Build as DLL)	25m 30s
	6h 50m 56s

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