[BUG] #1435 breaks automated builds on Windows

**Describe the bug**
My CI automatically clones the main branch using CMake FetchContent. My Windows CI builds are now failing as of #1435. Specifically, the following linker error appears:

```
bench_delayed.obj : error LNK2019: unresolved external symbol "__declspec(dllimport) public: struct benchmark::State::StateIterator __cdecl benchmark::State::begin(void)" (__imp_?begin@State@benchmark@@QEAA?AUStateIterator@12@XZ) referenced in function "void __cdecl bench_tokens(class benchmark::State &)" (?bench_tokens@@YAXAEAVState@benchmark@@@Z) [D:\a\parlaylib\parlaylib\build\benchmark\bench_delayed.vcxproj]
bench_delayed.obj : error LNK2019: unresolved external symbol "__declspec(dllimport) public: struct benchmark::State::StateIterator __cdecl benchmark::State::end(void)" (__imp_?end@State@benchmark@@QEAA?AUStateIterator@12@XZ) referenced in function "void __cdecl bench_tokens(class benchmark::State &)" (?bench_tokens@@YAXAEAVState@benchmark@@@Z) [D:\a\parlaylib\parlaylib\build\benchmark\bench_delayed.vcxproj]
bench_delayed.obj : error LNK2019: unresolved external symbol "__declspec(dllimport) public: __int64 __cdecl benchmark::State::range(unsigned __int64)const " (__imp_?range@State@benchmark@@QEBA_J_K@Z) referenced in function "void __cdecl bench_tokens(class benchmark::State &)" (?bench_tokens@@YAXAEAVState@benchmark@@@Z) [D:\a\parlaylib\parlaylib\build\benchmark\bench_delayed.vcxproj]
bench_delayed.obj : error LNK2019: unresolved external symbol "__declspec(dllimport) public: __cdecl benchmark::internal::FunctionBenchmark::FunctionBenchmark(char const *,void (__cdecl*)(class benchmark::State &))" (__imp_??0FunctionBenchmark@internal@benchmark@@QEAA@PEBDP6AXAEAVState@2@@Z@Z) referenced in function "void __cdecl `dynamic initializer for 'benchmark_uniq_2_benchmark_''(void)" (??__Ebenchmark_uniq_2_benchmark_@@YAXXZ) [D:\a\parlaylib\parlaylib\build\benchmark\bench_delayed.vcxproj]
bench_delayed.obj : error LNK2019: unresolved external symbol "__declspec(dllimport) public: virtual __cdecl benchmark::internal::FunctionBenchmark::~FunctionBenchmark(void)" (__imp_??1FunctionBenchmark@internal@benchmark@@UEAA@XZ) referenced in function "public: virtual void * __cdecl benchmark::internal::FunctionBenchmark::`scalar deleting destructor'(unsigned int)" (??_GFunctionBenchmark@internal@benchmark@@UEAAPEAXI@Z) [D:\a\parlaylib\parlaylib\build\benchmark\bench_delayed.vcxproj]
D:\a\parlaylib\parlaylib\build\benchmark\Debug\bench_delayed.exe : fatal error LNK1120: 5 unresolved externals [D:\a\parlaylib\parlaylib\build\benchmark\bench_delayed.vcxproj]
```

Downgrading to any previous commit works fine and fixes the error.

Here is an example CI run that demonstrates the issue: https://github.com/cmuparlay/parlaylib/runs/7453801262?check_suite_focus=true#step:5:6769 (build failed)

Here is an identical CI run of the same code, except that I downgraded Google Benchmark to v1.6.2: https://github.com/cmuparlay/parlaylib/runs/7454449941?check_suite_focus=true (build succeeded)

**System**
Which OS, compiler, and compiler version are you using:
- OS: Microsoft Windows Server 2022 10.0.20348 (windows-latest in Github Actions)
- Compiler and version: MSVC 19.32.31332.0

**To reproduce**
Steps to reproduce the behavior:
1. Checkout https://github.com/cmuparlay/parlaylib/tree/45433ca5425db200071feb60c58e965967112f40
2. mkdir build && cd build
3. cmake -A x64 -DCMAKE_BUILD_TYPE=Debug -DCMAKE_CXX_FLAGS=" /bigobj " -DPARLAY_BENCHMARK=On ..
4. cmake --build .
5. See error

**Expected behavior**
The build does not produce a linker error