fix: simplify macOS sleep inhibitor FFI (#12340)

Summary
- simplify the macOS sleep inhibitor FFI by replacing `dlopen` / `dlsym`
/ `transmute` with normal IOKit extern calls and `SAFETY` comments
- switch to cfg-selected platform implementations
(`imp::SleepInhibitor`) instead of `Box<dyn ...>`
- check in minimal IOKit bindings generated with `bindgen` and include
them from the macOS backend
- enable direct IOKit linkage in Bazel macOS builds by registering
`IOKit` in the Bazel `osx.framework(...)` toolchain extension list
- update `Cargo.lock` and `MODULE.bazel.lock` after removing the
build-time `bindgen` dependency path

Testing
- `just fmt`
- `cargo clippy -p codex-utils-sleep-inhibitor --all-targets -- -D
warnings`
- `cargo test -p codex-utils-sleep-inhibitor`
- `bazel test //codex-rs/utils/sleep-inhibitor:all --test_output=errors`
- `just bazel-lock-update`
- `just bazel-lock-check`

Context
- follow-up to #11711 addressing Ryan's review comments
- `bindgen` is used to generate the checked-in bindings file, but not at
build time

codex-rs/utils/sleep-inhibitor/src/lib.rs

@@ -6,31 +6,26 @@
 #[cfg(not(target_os = "macos"))]
 mod dummy;
 #[cfg(target_os = "macos")]
-mod macos_inhibitor;
+mod macos;
 
-use std::fmt::Debug;
+#[cfg(not(target_os = "macos"))]
+use dummy as imp;
+#[cfg(target_os = "macos")]
+use macos as imp;
 
 /// Keeps the machine awake while a turn is in progress when enabled.
 #[derive(Debug)]
 pub struct SleepInhibitor {
     enabled: bool,
-    platform: Box<dyn PlatformSleepInhibitor>,
-}
-
-pub(crate) trait PlatformSleepInhibitor: Debug {
-    fn acquire(&mut self);
-    fn release(&mut self);
+    platform: imp::SleepInhibitor,
 }
 
 impl SleepInhibitor {
     pub fn new(enabled: bool) -> Self {
-        #[cfg(target_os = "macos")]
-        let platform: Box<dyn PlatformSleepInhibitor> =
-            Box::new(macos_inhibitor::MacOsSleepInhibitor::new());
-        #[cfg(not(target_os = "macos"))]
-        let platform: Box<dyn PlatformSleepInhibitor> = Box::new(dummy::DummySleepInhibitor::new());
-
-        Self { enabled, platform }
+        Self {
+            enabled,
+            platform: imp::SleepInhibitor::new(),
+        }
     }
 
     /// Update the active turn state; turns sleep prevention on/off as needed.