Interpolating env vars with variables does not work

[ryanpodonnell1]

Description

$ task -t ./Taskfile2.yaml example
task: [example] echo 'account_'
account_

task -t Taskfile2.yaml example TIER=dev
task: [example] echo 'account_'
account_

Version

3.42.1

Operating system

linux

Experiments Enabled

No response

Example Taskfile

version: "3"

vars:
  TIER: '{{ .TIER | default "dev"}}'


env:
  AWS_PROFILE: "account_{{ .TIER }}"


tasks:
 example:
  cmds:
  - echo '{{ .AWS_PROFILE }}'