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/Cargo.toml

@@ -30,7 +30,7 @@ anyhow = "1.0.38"
 mach = "0.3.2"
 
 [target.'cfg(unix)'.dependencies]
-rsix = "0.23.2"
+rustix = "0.26.2"
 
 [target.'cfg(target_os = "windows")'.dependencies]
 winapi = { version = "0.3.7", features = ["winbase", "memoryapi", "errhandlingapi", "handleapi"] }