Accidentally removed array encoder (#80)

Why
===

During #69 I fixed a bug with `Any` type derivation, in so doing I
neglected to account for array encoders.

```diff
     async def stageFiles(
         self,
-        input: Any,
+        input: GitStagefilesInput,
     ) -> GitStagefilesOutput:
```

This fixes the following:
```diff
-            lambda x: x,
+            lambda x: TypeAdapter(List[FooBarBaz]).dump_python(
+                x,  # type: ignore[arg-type]
+                by_alias=True,
+                exclude_none=True,
+            ),
```

What changed
============

- Avoid incorrectly stubbing out array encoders

Test plan
=========

Manually running confirmed the fix

Author: blast-hardcheese

replit_river/codegen/client.py

@@ -531,10 +531,9 @@ def __init__(self, client: river.Client[{handshake_type}]):
                                     exclude_none=True,
                                   )
                 """.rstrip()
-            if (
-                isinstance(procedure.input, RiverConcreteType)
-                and procedure.input.type != "object"
-            ):
+            if isinstance(
+                procedure.input, RiverConcreteType
+            ) and procedure.input.type not in ["object", "array"]:
                 render_input_method = "lambda x: x"
 
             if output_type == "None":