Update to rustix 0.26.2. (#3521)

This pulls in a fix for Android, where Android's seccomp policy on older
versions is to make `openat2` irrecoverably crash the process, so we have
to do a version check up front rather than relying on `ENOSYS` to
determine if `openat2` is supported.

And it pulls in the fix for the link errors when multiple versions of
rsix/rustix are linked in.

And it has updates for two crate renamings: rsix has been renamed to
rustix, and unsafe-io has been renamed to io-extras.

crates/runtime/src/instance/allocator/pooling/uffd.rs

@@ -33,7 +33,7 @@
 use super::{InstancePool, MemoryPool};
 use crate::instance::Instance;
 use anyhow::{bail, Context, Result};
-use rsix::io::{madvise, Advice};
+use rustix::io::{madvise, Advice};
 use std::thread;
 use userfaultfd::{Event, FeatureFlags, IoctlFlags, Uffd, UffdBuilder};
 use wasmtime_environ::{DefinedMemoryIndex, EntityRef, MemoryInitialization};