Revert "test: add test case cannot_alloc_max_usize_minus_some"

This reverts commit 77b0c40.

Constructing such bug `Layout`s is now refused by `Layout::
from_size_align` as of [rust-lang/rust#95295][1].

[1]: rust-lang/rust#95295

Author: yvt

crates/rlsf/tests/global.rs

@@ -1,9 +1,6 @@
 // Adopted from
 // https://github.com/alexcrichton/dlmalloc-rs/blob/master/tests/global.rs
-use std::{
-    alloc::{GlobalAlloc, Layout},
-    collections::HashMap,
-};
+use std::collections::HashMap;
 
 #[global_allocator]
 #[cfg(any(all(target_arch = "wasm32", not(target_feature = "atomics")), unix))]
@@ -55,15 +52,3 @@ fn test_larger_than_word_alignment() {
         }
     }
 }
-
-#[test]
-fn cannot_alloc_max_usize_minus_some() {
-    // The test should complete without causing OOM
-    for offset in (0..64).step_by(8) {
-        let layout = Layout::from_size_align(usize::MAX - offset, 1).unwrap();
-        for _ in 0..1000000 {
-            let result = unsafe { A.alloc(layout) };
-            assert!(result.is_null());
-        }
-    }
-}