[TEST] Fix lifetime issues in prometheus test utils #8504

Job	Run time
CMake clang 14 (maintainer mode, sync)	23m 56s
CMake gcc 12 (maintainer mode, async)	12m 4s
CMake gcc 12 (maintainer mode, C++11, async)	12m 52s
CMake gcc 12 (maintainer mode, sync)	11m 40s
CMake test (without otlp-exporter)	6m 16s
CMake test (with abseil)	7m 10s
CMake clang 14 (maintainer mode, async)	17m 16s
CMake gcc 4.8 (with otlp exporter)	15m 5s
CMake gcc 4.8 (without otlp exporter)	6m 46s
CMake msvc (maintainer mode)	10m 19s
CMake test (with opentracing-shim)	9m 3s
CMake test (with otlp-exporter)	20m 25s
CMake C++20 test(Clang with libc++)	17m 10s
CMake C++20 test(GCC)	16m 17s
CMake test (without otlp-exporter and with async export)	9m 3s
Bazel asan config	13m 45s
Bazel noexcept	18m 58s
Bazel nortti	19m 55s
Bazel on MacOS	26m 13s
Bazel	24m 22s
Bazel with async export	24m 40s
Bazel tsan config	21m 4s
Bazel valgrind	26m 55s
Bazel with external abseil	18m 56s
Benchmark	12m 15s
CMake do not install test (with otlp-exporter)	20m 58s
CMake install test (with abseil)	8m 47s
CMake test (with modern protobuf,grpc and abseil)	29m 57s
CMake test (build shared libraries with otlp-exporter and static gRPC)	28m 23s
Plugin -> CMake	1m 6s
Code coverage	13m 11s
Copyright	10s
DocFX check	42s
Format	19s
markdown-lint	7s
misspell	4s
CMake -> exporter proto	24m 30s
Bazel Windows	37m 15s
Plugin -> CMake Windows	10m 2s
CMake -> exporter proto (Build as DLL)	17m 37s
CMake (With async export) -> exporter proto	18m 18s
	10h 13m 51s

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