[API] Propagators: do not overwrite the active span with a default in… #9116

Job	Run time
Bazel noexcept	11m 54s
Bazel asan config	14m 56s
Bazel nortti	12m 40s
Bazel on MacOS	30m 21s
Bazel	12m 30s
Bazel with async export	12m 26s
Bazel tsan config	13m 14s
Bazel valgrind	14m 2s
Bazel with external abseil	12m 57s
Benchmark	7m 54s
CMake test (with abseil)	4m 42s
CMake clang 15 (maintainer mode, abiv2)	14m 16s
CMake clang 15 (maintainer mode, async)	14m 37s
CMake clang 15 (maintainer mode, sync)	13m 55s
CMake do not install test (with otlp-exporter)	13m 53s
CMake gcc 13 (maintainer mode, async)	6m 45s
CMake gcc 13 (maintainer mode, sync)	6m 41s
CMake install test (with abseil)	4m 23s
CMake test (with modern protobuf,grpc and abseil)	17m 50s
CMake msvc (maintainer mode)	7m 47s
CMake msvc (maintainer mode) with C++20	7m 49s
CMake test (with opentracing-shim)	4m 34s
CMake test (build shared libraries with otlp-exporter and static gRPC)	13m 39s
CMake test (with otlp-exporter)	13m 59s
CMake test (without otlp-exporter)	5m 1s
CMake C++14 test(GCC)	3m 59s
CMake C++17 test(GCC)	5m 40s
CMake C++20 test(Clang with libc++)	10m 10s
CMake C++20 test(GCC)	8m 50s
CMake C++23 test(Clang with libc++)	9m 7s
CMake C++23 test(GCC)	8m 32s
CMake test (without otlp-exporter and with async export)	4m 42s
Code coverage	11m 29s
Copyright	6s
DocFX check	38s
Format	15s
markdown-lint	6s
misspell	4s
Plugin -> CMake	1m 11s
CMake -> exporter proto	12m 34s
Bazel Windows	23m 27s
Plugin -> CMake Windows	6m 35s
CMake (With async export) -> exporter proto	12m 37s
CMake -> exporter proto (Build as DLL)	29m 4s
	7h 21m 51s

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