macos: core: macOS coroutine unstability fixes

[cosmo0920]

In macOS, the size of pthread stack min of Intel Mac (x64) and Apple Silicon (M1/M2) is smaller than the Linux one.
This means that the concrete values are:

Intel Mac

PTHREAD_STACK_MIN = 8192
(3 * PTHREAD_STACK_MIN) / 2 = 12288 which means fluent-bit's minimum stack size

Apple Silicon

PTHREAD_STACK_MIN = 16384
(3 * PTHREAD_STACK_MIN) / 2 = 24576 which means fluent-bit's minimum stack size

They shouldn't be enough for libresolv API which needs to use heap memories: res_ninit(statep).

When increasing the coroutine size to:

24576 bytes (24KiB) on Intel Mac and 36864 bytes (36KiB) on Apple Silicon respectively, the heap memory corruptions are not occurred.

Related to #7670.

additional contexts

I tested for the minimum code:

#include <stdio.h>
#include <limits.h>

#ifdef FLB_CORO_STACK_SIZE
#define FLB_CORO_STACK_SIZE_BYTE      FLB_CORO_STACK_SIZE
#else
#define FLB_CORO_STACK_SIZE_BYTE      ((3 * PTHREAD_STACK_MIN) / 2)
#endif

int main(void)
{
    unsigned int size = FLB_CORO_STACK_SIZE_BYTE;

    printf("pthread stack min size = %u\n", PTHREAD_STACK_MIN);

    size = (size + 1023) & ~1023;
    printf("flb stack size = %u\n", size);

    return 0;
}

The canary CI results are:
https://github.com/fluent/fluent-bit/actions/runs/5832454631
https://github.com/fluent/fluent-bit/actions/runs/5832456028
https://github.com/fluent/fluent-bit/actions/runs/5832457491

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