Bump external/benchmark from `c19cfee` to `08fdf6e` #1917

Job	Run time
clang-tidy	1m 7s
cppcheck	1m 0s
cmake-lint	26s
code-ql (cpp, gcc-14)	2m 45s
include-what-you-use	45s
msvc-code-analysis (RelWithDebInfo)	5m 24s
Codacy Security Scan	2m 57s
DevSkim	29s
ShellCheck	10s
	15m 3s

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