fix: cpu concurrency detection on some platforms

[thunder-coding]

os.availableParallelism() should produce more accurate results of how
much parallelism should be used then os.cpus().length. The only
breaking change is the newer API requires node versions >= v18.x which
is fine as node-gyp only aims to support latest and LTS releases. And
the oldest LTS release still supported as of this commit is v22.

Fixes #3191

This should improve Android support.

Checklist

• npm install && npm run lint && npm test passes
• tests are included
• documentation is changed or added
• commit message follows commit guidelines

Description of change

[cclauss]

Are there docs that explain how the CPU count will change on Android?

[thunder-coding]

No, no straightforward docs, but this should give you an explaination.

From API docs for os.cpus()

os.cpus().length should not be used to calculate the amount of parallelism available to an application. Use os.availableParallelism() for this purpose.

Looking at source tree of Node.js:

• os.cpus() relies on exposed getCPUs() internal binding
• Native C++ code for getCPUs() is implemented in another C++ routine
• This internally relies on libuv's uv_get_cpus()
• Implementation of libuv's uv_get_cpus() reveals that it will error out if /proc/stat is not readible. In case of Android /proc/stat is restricted in newer Android versions

So on newer Android versions os.cpus() returns an empty array. os.cpus().length evaluates to 0. os.getParallelism() on the other hand gives an accurate answer.

I believe that the docs specifying that os.cpus() not being a reliable way to get number of parallelism is a enough answer for this change. os.getParallelism() does solve this problem effectively

If you want I can include these details in the commit message as well (I didn't as I thought it would make the commit message bit too long)