Reduce thread count on 32-bit in GetTotalAllocatedBytes.TestAnotherThread

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GC/API/GC/GetTotalAllocatedBytes intermittently fails with OutOfMemoryException on linux-arm Checked jitstress: rapidly creating 1000 threads exhausts the 32-bit address space.

Changes

• src/tests/GC/API/GC/GetTotalAllocatedBytes.cs
  • TestAnotherThread: cap the inner thread-creation loop at 100 on 32-bit (IntPtr.Size == 4); 64-bit keeps the original 1000.
  • Remove the [ActiveIssue(..., IsArm)] suppression so the test runs on 32-bit ARM again.

// 1000 quickly created threads can be too many for a 32-bit environment, so reduce on 32-bit.
int threadCount = IntPtr.Size == 4 ? 100 : 1000;

tsk = Task.Run(() => {
    for (int i = 0; i < threadCount; i++)
    {
        ...
    }
});

Note

This PR description and the contained changes were generated with assistance from GitHub Copilot.

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Pull request overview

Reduces intermittent OutOfMemoryException failures in the GC/API/GC/GetTotalAllocatedBytes test on 32-bit Linux ARM by lowering the amount of thread creation pressure, and re-enables the test on ARM by removing an ActiveIssue suppression.

Changes:

• Cap the thread-creation loop in TestAnotherThread to 100 iterations on 32-bit processes (keep 1000 on 64-bit).
• Remove the ARM-specific [ActiveIssue(... IsArm)] suppression so the test runs on ARM again.