fix(mt): satisfy serial wait loop lint

Use an explicit break-based loop for the Rust serial wait projection so
Clippy recognizes that the C wait callback can change the shared job counter.
The loop preserves the same lock ownership and condition-wait behavior.

Test Plan:
- cargo fmt --manifest-path rust/Cargo.toml -- --check
- ulimit -v 41943040 && CARGO_BUILD_JOBS=1 cargo clippy --manifest-path rust/Cargo.toml --all-targets -- -D warnings

rust/src/zstdmt_compress.rs

@@ -133,7 +133,10 @@ pub unsafe extern "C" fn ZSTDMT_rust_serialStateWaitForTurn(
 
     unsafe {
         lock(state.callback_context);
-        while *state.next_job_id < state.job_id {
+        loop {
+            if *state.next_job_id >= state.job_id {
+                break;
+            }
             wait(state.callback_context);
         }
         c_int::from(*state.next_job_id == state.job_id)