Let rustfmt have the assertion it reflowed

The closure taken down to `&dyn Operation` needed its call site re-wrapped,
and I wrapped it by hand rather than letting rustfmt decide: it fits on one
line at the workspace width. `cargo clippy` was run on the change and
`cargo fmt --check` was not, which is the whole of how it got through — the
two catch different things and CI runs both.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>

core/dr-pipeline/src/mask.rs

@@ -1519,8 +1519,7 @@ mod tests {
             );
         }
         assert!(
-            ids.len() < global.len()
-                || global.iter().all(|op| local_means_something(op.as_ref())),
+            ids.len() < global.len() || global.iter().all(|op| local_means_something(op.as_ref())),
             "the filter dropped nothing, so either it is not running or the \
              chain has nothing left that a layer cannot carry"
         );