google.protobuf.message.DecodeError when passed objects with nested levels above 30

首先，使用 issue 中展示的嵌套 composite manifest 重现该失败，然后跟踪报告 google.protobuf.message.DecodeError 的 RunFunctionRequest 的序列化和解码过程。将深度嵌套输入值的处理方式与所提到的成功的 output-resource 情况进行比较；当函数调用能够接受所示嵌套而不出现该解码错误时，即表示完成。

What happened?

We have composition that generates or consumes values with a high level of nested sub-values. (Those are CRDs that we are using with the Kubernetes Provider)
When going over 30 levels of imbrication the error below is raised

crossplane: error: cannot render composite resource: cannot run pipeline step "blueprint": rpc error: code = Unknown desc = Unexpected <class 'google.protobuf.message.DecodeError'>: Error parsing message with type 'apiextensions.fn.proto.v1.RunFunctionRequest'

How can we reproduce it?

`
apiVersion:  <APIVERSION>
kind: XCOMPO
metadata:
  name: <NAME>
spec:
  debug:
    level0:
      level1:
        level2:
          level3:
            level4:
              level5:
                level6:
                  level7:
                    level8:
                      level9:
                        level10:
                          level11:
                            level12:
                              level13:
                                level14:
                                  level15:
                                    level16:
                                      level17:
                                        level18:
                                          level19:
                                            level20:
                                              level21:
                                                level22:
                                                  level23:
                                                    level24:
                                                      level25:
                                                        level26:
                                                          level27:
                                                            level28:
                                                              level29:

Running ☝ this composite would faild if there is a level30 as child of level29.

Could this be linked to the limits set in Protobuf (https://github.com/protocolbuffers/protobuf/issues/6537) ?

Note: there is no issue when outputing resources with more than 30 levels. (ie: running something like

rsp.desired.resources["toto"].resource.update(resources)

Where resources has more than 30 levels.
It is only when the function is called with too many depth inputs that the exception is raised.

What environment did it happen in?

Function version:
0.6.0