Revert "Use `mmap` `std.heap.page_allocator` impl when compiling for Wasm + libc"
This reverts commit c9fa8e46df21cdf66b291fb3dfdcef1b6a1d3cab.
This commit was failing CI checks. This failure was unfortunately not
noticed before merge, due in part to the build runner bug fixed in the
last commit.
04226193ccMatthew Lugg committed on 1/3/2026, 2:52:17 PMparentd024d9f