Fix API usage for getting an MLIR interface for an operation

This method is an implementation details of the interface mechanism and is
documented as "this should not be used directly". Instead operation should be
"dyn_casted" into the interface directly.

PiperOrigin-RevId: 364723086

iree/compiler/Dialect/VM/Target/Bytecode/BytecodeEncoder.cpp

@@ -298,14 +298,14 @@ Optional<EncodedBytecodeFunction> BytecodeEncoder::encodeFunction(
     }
 
     for (auto &op : block.getOperations()) {
-      auto *serializableOp =
-          op.getAbstractOperation()->getInterface<IREE::VM::VMSerializableOp>();
+      auto serializableOp =
+          dyn_cast<IREE::VM::VMSerializableOp>(op);
       if (!serializableOp) {
         op.emitOpError() << "is not serializable";
         return llvm::None;
       }
       if (failed(encoder.beginOp(&op)) ||
-          failed(serializableOp->encode(&op, symbolTable, encoder)) ||
+          failed(serializableOp.encode(symbolTable, encoder)) ||
           failed(encoder.endOp(&op))) {
         op.emitOpError() << "failed to encode";
         return llvm::None;