Azure DevOps pwsh and PowerShell@2 fail to execute inside docker image

Background Setup:In our organization we are using Azure virtual machine scale sets (VMSS), specification is shown in image below: to use as self hosted agents for our DevOps pipelines. We are running all our DevOps pipeline jobs in docker containers pulled into the VMSS. The jobs are executing properly, except for the ones which have powershell task, either as pwsh or PowerShell@2. Both of them are failing with the following error:

##[error]Unable to locate executable file: 'pwsh'. Please verify either the file path exists or the file can be found within a directory specified by the PATH environment variable. Also check the file mode to verify the file is executable.

Spec of the VMSS:

Here is the screen shot of the error:

The docker image I am using to run the job inside however, has powershell installed. Below is the docker image file:

FROM python:3.10-slim
ENV TERRAFORM_VERSION=1.0.4
ENV KUBECTL_VERSION=v1.25.2
ENV HELM_VERSION=v3.10.0
ENV PIP_VERSION=22.3
ENV CHECKOV_VERSION=2.1.270
ENV YQ_VERSION=3.1.0
ENV TZ=UTC
ENV DEBIAN_FRONTEND=noninteractive

USER 0
HEALTHCHECK NONE

# install packages
RUN apt-get update && apt-get install -yq --no-install-recommends \
    git \
    curl \
    unzip \
    jq \
    wget \
# install versioned terraform, kubectl and helm binary
    && curl -sLO https://releases.hashicorp.com/terraform/${TERRAFORM_VERSION}/terraform_${TERRAFORM_VERSION}_linux_amd64.zip \
    && unzip terraform_${TERRAFORM_VERSION}_linux_amd64.zip \
    && mv terraform /usr/local/bin/ \
    && chmod +x /usr/local/bin/terraform \
    && curl -sLO https://storage.googleapis.com/kubernetes-release/release/${KUBECTL_VERSION}/bin/linux/amd64/kubectl \
    &&  chmod +x ./kubectl \
    && mv ./kubectl /usr/local/bin \
    && curl -sLO https://get.helm.sh/helm-${HELM_VERSION}-linux-amd64.tar.gz \
    && tar -xzf helm-${HELM_VERSION}-linux-amd64.tar.gz \
    && mv linux-amd64/helm /bin/helm && rm -rf linux-amd64 \
## install powershell    
    && wget -q https://packages.microsoft.com/config/debian/10/packages-microsoft-prod.deb \
    && dpkg -i packages-microsoft-prod.deb  \
    && apt-get update && apt-get install -y powershell \
#     pwsh Register-PSRepository \
# install checkov and yq via pip
    && pip3 install --no-cache-dir checkov==${CHECKOV_VERSION} \
    && pip3 install --no-cache-dir yq==${YQ_VERSION} \
# cleanup
    && apt-get autoremove --purge -y \
    && apt-get clean \
    && rm -rf /var/lib/apt/lists/* \
    && rm -rf *.zip *.gz


################################
# Install Azure CLI
################################
RUN curl -sL https://aka.ms/InstallAzureCLIDeb | bash

As you see in docker image powershell is installed, but still the job is causing error. Below I show the DevOps pipeline job that is causing failure:

pool: my-VMSS-devops-pool
resources:
  containers:
  - container: base
    image: mycontainerregistry.azurecr.io/black/base-image:1.1.0
    endpoint: 'service-connection-endpoint-to-ACR'

trigger:
  branches:
    include:
      - "main"
      - "feature/*"
## Some variables here
stages:
  - stage: Build
    displayName: 'Build Stage'

    jobs:
    - job: SomeJobe
      steps:
        - task: PowerShell@2
          inputs:
            targetType: 'inline'
            pwsh: true
            script:
              Write-Host "$(deployToDevPipelineLvl) - ${{variables.deployToDevPipelineLvl}}"
              Write-Host "$(deployToQAPipelineLvl) - ${{variables.deployToQAPipelineLvl}}"
              Write-Host "$(deployToProdPipelineLvl) - ${{variables.deployToProdPipelineLvl}}"
          displayName: pwsh check var values

    - job: build_publish_whlPackageName
      steps:
        - task: UsePythonVersion@0
          displayName: Use Python $(pythonVersion)
          inputs:
            versionSpec: $(pythonVersion)

## The rest of the pipeline

The task: PowerShell@2 is the part that is causing the error. Please note that I tried "pwsh" but it is also raising the same error.

- pwsh: |
    ## Code goes here

In short the question is how should I make changes to the docker image, if the problem is from the docker image side, to resolve the error and be able to execute Azure DevOps powershell tasks inside a docker container in a self-hosted VMSS?

It seems you are missing the container definition in the jobs section:

jobs:
    - job: SomeJobe
      container:
        image: mycontainerregistry.azurecr.io/black/base-image:1.1.0
        endpoint: 'service-connection-endpoint-to-ACR'
      steps:
        - task: PowerShell@2
          inputs:
            targetType: 'inline'
            pwsh: true
            script:
              Write-Host "$(deployToDevPipelineLvl) - ${{variables.deployToDevPipelineLvl}}"
              Write-Host "$(deployToQAPipelineLvl) - ${{variables.deployToQAPipelineLvl}}"
              Write-Host "$(deployToProdPipelineLvl) - ${{variables.deployToProdPipelineLvl}}"
          displayName: pwsh check var values

jobs:  
  - job: Run_Prod
    displayName: Build_Prod
    container:
      image: ${{ variables.buildContainerUrl }}
      endpoint: ${{ variables.containerRegistryServiceConnection }}
      options: --user 0:0