[BUG] Core Affinity doesn't seem to work (Or Reporter wrong?)

**Describe the bug**
I would like to run the benchmark on a particular CPU core. The [docs]( says:

```
2. Set the benchmark program's task affinity to a fixed cpu. For example:
```sh
taskset -c 0 ./mybenchmark
```
However, when I run the `basic_test` app, I see the following:
```
build git:(main) taskset -c 0 ./test/basic_test
2024-07-11T11:29:31+02:00
Running ./test/basic_test
Run on (24 X 4700 MHz CPU s)
CPU Caches:
L1 Data 48 KiB (x12)
L1 Instruction 32 KiB (x12)
L2 Unified 1280 KiB (x12)
L3 Unified 25600 KiB (x1)
Load Average: 5.07, 4.92, 2.97
***WARNING*** CPU scaling is enabled, the benchmark real time measurements may be noisy and will incur extra overhead.
-----------------------------------------------------------------------------------------
Benchmark Time CPU Iterations
-----------------------------------------------------------------------------------------
BM_empty 0.327 ns 0.325 ns 2148747493
BM_empty/threads:24 0.296 ns 0.328 ns 2130524928
...
```
I think it might be reporting here that is wrong. Looking at `top`, I can verify that only core 0 is used. The code in `reporter`[https://github.com/google/benchmark/blob/main/src/reporter.cc#L49C29-L49C37) seems to use a static number of cores.

**System**
Which OS, compiler, and compiler version are you using:
- OS: ubuntu 22.04
- Compiler and version: gcc 11.4

**To reproduce**
Steps to reproduce the behavior:
1. sync to commit : `ea71a14891474943fc1f34d359f9e0e82476ffe1`
2. cmake: ` cmake -D BENCHMARK_DOWNLOAD_DEPENDENCIES=1 -S . -B build`
3. make: `cmake --build build/ -j20`
4. `taskset -c 0 ./build/test/basic_test `

**Expected behavior**
I would expect the test to run only on core 0 and the output of the test be:
`Run on (1 X 4700 MHz CPU s)` instead of `Run on (24 X 4700 MHz CPU s)`