fix: `bits/unit_magnitude.h` added to CMake sources #1986

Job	Run time
Generate build matrix for Conan CI	4s
Apple Clang 15 C++20 fmtlib gsl-lite Debug	1h 31m 27s
Apple Clang 15 C++20 fmtlib none Release	1h 31m 25s
Clang-16 (x86-64) C++20 fmtlib gsl-lite Debug	2m 39s
Clang-16 (x86-64) C++20 fmtlib none Release	2m 52s
Clang-17 (x86-64) C++20 fmtlib none Debug	3m 26s
Clang-17 (x86-64) C++20 std::format gsl-lite Debug	4m 21s
Clang-18 (arm64) C++20 std::format gsl-lite Debug	1m 23s
Clang-18 (arm64) C++23 fmtlib none Release	1m 10s
Clang-18 (x86-64) C++20 std::format gsl-lite Debug	1m 39s
Clang-18 (x86-64) C++23 std::format none Debug	1m 31s
GCC-12 C++20 fmtlib gsl-lite Debug	5m 12s
GCC-12 C++20 fmtlib ms-gsl Release	4m 38s
GCC-12 C++23 fmtlib ms-gsl Debug	4m 34s
GCC-13 C++20 std::format gsl-lite Debug	3m 57s
GCC-13 C++20 std::format none Release	4m 9s
GCC-14 C++20 fmtlib none Release	3m 58s
GCC-14 C++20 std::format gsl-lite Debug	3m 39s
MSVC 14.4 C++20 fmtlib gsl-lite Debug	1m 46s
MSVC 14.4 C++20 std::format gsl-lite Debug	2m 5s
Promote Conan package	1s
	3h 55m 56s

Provide feedback