deep copying arraynode tasktemplate interface (#5479) (#322)

## Overview
Cherry picking [this PR from OSS](#5479).

## Test Plan
Tested with the following workflow as repro:
```
@task(cache=True, cache_version="1.0")
def bAr(a: int) -> List[int]:
    return [a + 1, a + 2]

@task(cache=True, cache_version="1.0")
def bAr2(a: int) -> List[int]:
    return [a + 1, a + 2]

@workflow
def my_wf_2(a: int) -> List[List[int]]:
    x = bAr(a=a)
    return map_task(bAr2)(a=x)
```

## Rollout Plan (if applicable)
May be immediatley rolled out

## Upstream Changes
Should this change be upstreamed to OSS (flyteorg/flyte)? If not, please uncheck this box, which is used for auditing. Note, it is the responsibility of each developer to actually upstream their changes. See [this guide](https://unionai.atlassian.net/wiki/spaces/ENG/pages/447610883/Flyte+-+Union+Cloud+Development+Runbook/#When-are-versions-updated%3F).
- [x] To be upstreamed to OSS

## Issue
https://linear.app/unionai/issue/COR-1132/arraynode-cache-data-type-does-not-match-issue

## Checklist
* [ ] Added tests
* [ ] Ran a deploy dry run and shared the terraform plan
* [ ] Added logging and metrics
* [ ] Updated [dashboards](https://unionai.grafana.net/dashboards) and [alerts](https://unionai.grafana.net/alerting/list)
* [ ] Updated documentation

flytepropeller/pkg/controller/nodes/array/node_execution_context.go

@@ -50,14 +50,14 @@ type arrayTaskReader struct {
 }
 
 func (a *arrayTaskReader) Read(ctx context.Context) (*core.TaskTemplate, error) {
-	taskTemplate, err := a.TaskReader.Read(ctx)
+	originalTaskTemplate, err := a.TaskReader.Read(ctx)
 	if err != nil {
 		return nil, err
 	}
 
 	// convert output list variable to singular
 	outputVariables := make(map[string]*core.Variable)
-	for key, value := range taskTemplate.Interface.Outputs.Variables {
+	for key, value := range originalTaskTemplate.Interface.Outputs.Variables {
 		switch v := value.Type.Type.(type) {
 		case *core.LiteralType_CollectionType:
 			outputVariables[key] = &core.Variable{
@@ -69,10 +69,14 @@ func (a *arrayTaskReader) Read(ctx context.Context) (*core.TaskTemplate, error)
 		}
 	}
 
-	taskTemplate.Interface.Outputs = &core.VariableMap{
-		Variables: outputVariables,
+	taskTemplate := *originalTaskTemplate
+	taskTemplate.Interface = &core.TypedInterface{
+		Inputs: originalTaskTemplate.Interface.Inputs,
+		Outputs: &core.VariableMap{
+			Variables: outputVariables,
+		},
 	}
-	return taskTemplate, nil
+	return &taskTemplate, nil
 }
 
 type arrayNodeExecutionContext struct {