http.post does not work in task

__Steps to reproduce:__
I used the following flux script to delete data when some criteria meet, while in curl or query, it works fine. But when i put it in task, then it fails to work.
```
import "http"
import "json"
from(bucket: "systembucket")
|> range(start: v.timeRangeStart, stop: v.timeRangeStop)
|> filter(fn: (r) => r["_measurement"] == "test")
|> aggregateWindow(every: 24h, fn: last, createEmpty: false)
|> limit(n:1)
|> map(fn: (r) =>
({r with jsonStr: string(v: json.encode(v: {"start": "2021-01-11T22:00:00Z", "stop": "2021-01-13T00:00:00Z", "predicate": "_measurement=\"cpu\""}))}))
|> map(fn: (r) =>
({r with status_code: http.post(url: "http://localhost:8086/api/v2/delete?org=testorg&bucket=testbucket", headers: {"Content-Type": "application/json", Authorization: "Token "}, data: bytes(v: r.jsonStr))}))
```

__Expected behavior:__
Data should be deleted as post request

__Actual behavior:__
Nothing happened. No error in log.

__Environment info:__
Influxdb v2.0.3

Start by reproducing the supplied Flux script as a task on InfluxDB v2.0.3, comparing it with the working curl or query behavior. Investigate the task execution path for http.post and determine how the request and any errors are handled. Done means the POST executes from a task and the expected data deletion occurs with an observable failure if it cannot run.

Written by the indexing model from the issue text.