Max linker memory being set for wasi thread builds

[brettcannon]

Bug report

Bug description:

The max memory for WASI thread builds is set at:

https://github.com/python/cpython/blob/1a2e7a747540f74414e7c50556bcb2cc127e9d1c/configure.ac#L2408C59-L2408C67

But that's not enough for a build anymore:

https://github.com/brettcannon/cpython-wasi-build/actions/runs/9704017614/job/26783382753#step:7:3581

Either the limit needs to increase to at least 20971520 or be dropped entirely (probably the latter).

CPython versions tested on:

CPython main branch

Operating systems tested on:

Other

[brettcannon]

dicej@118e9d8 suggests the settings might not even be necessary anymore.

[brettcannon]

Along the way the target triple should get updated to wasm32-wasip1-threads once #123877 is fixed.