Not able to set/access the latest value of variable in conditions on Azure Devops Pipeline

I have a Azure pipeline containing a job with a structure like this:

jobs:
  - job: A
    variables:
    - name: runJob
      value: true
    steps:
    - task: Powershell@2
      displayName: Evaluate runJob
      inputs:
        targetType: inline
        script: |
          <do some processing>
          echo "##vso[task.setvariable variable=runJob; isOutput=true]false"
          echo "##vso[task.setvariable variable=runJob]false"
          echo "New value for runJob: $(runJob)"
    
    - ${{ if eq(variables['runJob'], 'true') }}
      - checkout: self
      - execute remaining steps below ...

I'm able to execute the whole pipeline with runJob as 'true' but when the required conditions are met, the value of runJob should have been set as false using task.setVariable which is not happening. I tried with both ways with and without isOutput=true but the value of the variable still remains true and the pipeline is executing the remaining steps.

I need to update the variable value and want it to access the variable value as part of the condition.

jobs:
- job: A
  variables:
  - name: runJob
    value: True
  steps:
  - task: Powershell@2
    name: step1
    displayName: Evaluate runJob
    inputs:
      targetType: inline
      script: |
        Write-Host "##vso[task.setvariable variable=runJob; isOutput=true]False"

        Write-Host "New value for runJob: $(runJob)"

  - task: PowerShell@2
    name: step2
    displayName: Next display
    condition: eq(variables['runJob'], 'False')
    inputs:
      targetType: inline
      script: |
        Write-Host "New value for runJob $(runJob)"