test: increase allocation so it fails for the test

[AdamMajer]

It used to be impossible to allocate 1e10 bytes but with a v8 update this allocation can succeed. This results in 2x10GB allocations and failure to test the failure :-)

Increase allocation to 1e20 bytes, which should fail for some time, returning the test to using only 50MB at runtime.

Fixes: https://github.com/nodejs/node/issues/53085