[CI] Move the sing and notarize steps to a VM.

We do not have any special requirements to perform the signing except
for the fact that needs to be EO complient. The new vm allows us to be
 EO complient and reduces the number of real bots that we use.

tools/devops/automation/build-pipeline.yml

@@ -346,8 +346,6 @@ stages:
         keyringPass: $(pass--lab--mac--builder--keychain)
         enableDotnet: ${{ parameters.enableDotnet }}
         skipESRP: ${{ parameters.skipESRP }}
-        pool: ${{ parameters.pool }}
-
 
 - ${{ if eq(parameters.enableAPIDiff, true) }}:
   - stage: generate_api_diff

tools/devops/automation/templates/build/prepare-pkg-stage.yml

@@ -11,10 +11,6 @@ parameters:
   type: boolean
   default: false # only to be used when testing the CI and we do not need a signed pkg
 
-- name: pool
-  type: string
-  default: automatic
-
 jobs:
 - job: configure
   displayName: 'Configure build'
@@ -28,40 +24,13 @@ jobs:
   steps:
   - template: ../common/configure.yml
 
-- ${{ if eq(parameters.pool, 'automatic') }}:
-  - job: AgentPoolSelector       # https://docs.microsoft.com/en-us/azure/devops/pipelines/process/phases?view=azure-devops&tabs=yaml
-    pool:                        # Consider using an agentless (server) job here, but would need to host selection logic as an Azure function: https://docs.microsoft.com/en-us/azure/devops/pipelines/yaml-schema?view=azure-devops&tabs=schema#server
-      vmImage: ubuntu-latest
-    steps:
-    - checkout: none             # https://docs.microsoft.com/en-us/azure/devops/pipelines/yaml-schema?view=azure-devops&tabs=schema#checkout
-
-    # Selects appropriate agent pool based on trigger type (PR or CI); manually triggered builds target the PR pool
-    - template: azure-devops-pools/agent-pool-selector.yml@templates
-      parameters:
-        agentPoolPR: $(PRBuildPool)
-        agentPoolPRUrl: $(PRBuildPoolUrl)
-        agentPoolCI: $(CIBuildPool)
-        agentPoolCIUrl: $(CIBuildPoolUrl)
-
 - job: sign_notarize
   dependsOn:
-  - ${{ if eq(parameters.pool, 'automatic') }}:
-    - AgentPoolSelector
   - configure
   displayName: 'Sign & Notarize'
   timeoutInMinutes: 1000
-  variables:
-    ${{ if eq(parameters.pool, 'automatic') }}:
-      AgentPoolComputed: $[ dependencies.AgentPoolSelector.outputs['setAgentPool.AgentPoolComputed'] ]
-    ${{ if eq(parameters.pool, 'ci') }}:
-      AgentPoolComputed: $(CIBuildPool)
-    ${{ if eq(parameters.pool, 'pr') }}:
-      AgentPoolComputed: $(PRBuildPool)
   pool:
-    name: $(AgentPoolComputed)
-    demands:
-    - Agent.OS -equals Darwin
-    - macios_image -equals v2.1     # Big Sur image with Xcode 12.4 and 12.5 installed
+    vimImage: internal-macos12
   workspace:
     clean: all