Fix warnings #59

Job	Run time
Bazel noexcept	8m 44s
Bazel asan config	13m 58s
Bazel nortti	6m 44s
Bazel on MacOS	8m 47s
Bazel	17m 24s
Bazel with async export	7m 16s
Bazel tsan config	7m 16s
Bazel valgrind	8m 26s
Bazel with external abseil	8m 51s
Benchmark	2m 41s
CMake test (with abseil)	6m 17s
CMake clang 14 (maintainer mode, async)	17m 30s
CMake clang 14 (maintainer mode, sync)	17m 15s
CMake do not install test (with otlp-exporter)	19m 57s
CMake gcc 4.8 (with otlp exporter)	14m 49s
CMake gcc 4.8 (without otlp exporter)	5m 55s
CMake gcc 12 (maintainer mode, async)	15m 54s
CMake gcc 12 (maintainer mode, C++11, async)	10m 48s
CMake gcc 12 (maintainer mode, sync)	13m 10s
CMake install test (with abseil)	7m 44s
CMake test (with modern protobuf,grpc and abseil)	34m 16s
CMake msvc (maintainer mode)	17m 14s
CMake test (with opentracing-shim)	6m 34s
CMake test (build shared libraries with otlp-exporter and static gRPC)	20m 27s
CMake test (with otlp-exporter)	24m 15s
CMake test (without otlp-exporter)	6m 36s
CMake C++20 test(Clang with libc++)	15m 45s
CMake C++20 test(GCC)	16m 8s
CMake test (without otlp-exporter and with async export)	8m 17s
Code coverage	18m 41s
Copyright	8s
Format	14s
DocFX check	1m 10s
markdown-lint	12s
Plugin -> CMake	1m 42s
misspell	8s
CMake -> exporter proto	19m 59s
Bazel Windows	36m 3s
Plugin -> CMake Windows	10m 3s
CMake (With async export) -> exporter proto	24m 2s
CMake -> exporter proto (Build as DLL)	23m 44s
	8h 25m 4s

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