Drop the last two lint expectations clippy 1.98 no longer fulfils (#8568)

Assisted-by: Claude Code:claude-opus-5

crates/host_env/src/posix.rs

@@ -1406,10 +1406,6 @@ fn build_posix_spawn_attrs(
             target_os = "illumos",
             target_os = "hurd",
         )))]
-        #[expect(
-            clippy::std_instead_of_core,
-            reason = "false positive: core::io::ErrorKind is unstable (core_io); expect is co-gated with the usage so it is not left unfulfilled on platforms where this block is compiled out"
-        )]
         {
             return Err(std::io::Error::new(
                 std::io::ErrorKind::Unsupported,

crates/vm/src/stdlib/_signal.rs

@@ -337,10 +337,6 @@ pub(crate) mod _signal {
         }
 
         #[cfg(windows)]
-        #[expect(
-            clippy::std_instead_of_core,
-            reason = "false positive: core::io::ErrorKind is unstable (core_io)"
-        )]
         let is_socket = if fd != INVALID_WAKEUP {
             host_signal::wakeup_fd_is_socket(fd).map_err(|err| {
                 if err.kind() == std::io::ErrorKind::InvalidInput {