Cleanup: Use fixed width integer for int results

We use fixed width integers in the variant definition, so retrieve using
fixed width as well.

source/blender/nodes/composite/nodes/node_composite_file_output.cc

@@ -728,7 +728,7 @@ class FileOutputOperation : public NodeOperation {
         return buffer;
       }
       case ResultType::Int: {
-        const float value = float(result.get_single_value<int>());
+        const float value = float(result.get_single_value<int32_t>());
         CPPType::get<float>().fill_assign_n(&value, buffer, length);
         return buffer;
       }