Fix runners.py to use functools.partial instead of removed unroll_kwargs

The unroll_kwargs parameter was removed from bm.for_loop() as it was never
actually implemented. Updated runners.py to use functools.partial() to bind
shared_args to _step_func_predict, following the pattern already used in
train/online.py.

Changes:
- Added functools import
- Changed for_loop call to use functools.partial(self._step_func_predict, shared_args=shared_args)
- Removed unroll_kwargs={'shared_args': shared_args} which was non-functional

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude <noreply@anthropic.com>

Author: Routhleck

brainpy/runners.py

@@ -13,6 +13,7 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 # ==============================================================================
+import functools
 import inspect
 import time
 import warnings
@@ -662,8 +663,7 @@ def _fun_predict(self, indices, *inputs, shared_args=None):
             return outs, None
 
         else:
-            return bm.for_loop(self._step_func_predict,
+            return bm.for_loop(functools.partial(self._step_func_predict, shared_args=shared_args),
                                (indices, *inputs),
                                jit=self.jit['predict'],
-                               unroll_kwargs={'shared_args': shared_args},
                                progress_bar=self.progress_bar)