ci: Use Ubuntu for publish job (#2256)

* Revert "ci: Use the same VM image for PR and publish"

This reverts commit e2b6374.

* ci: specify publish pool with `os`

* Use Ubuntu instead

Author: Saadnajmi

.ado/publish.yml

@@ -55,7 +55,9 @@ extends:
          - job: RNGithubNpmJSPublish
            displayName: NPM Publish React-native-macos
            pool:
-             vmImage: $(vmImageApple)
+             name: cxeiss-ubuntu-20-04-large
+             image: cxe-ubuntu-20-04-1es-pt
+             os: linux
            variables:
              - name: BUILDSECMON_OPT_IN
                value: true

.ado/templates/apple-steps-publish.yml

@@ -2,8 +2,6 @@ parameters:
   build_type: ''
 
 steps:
-  - template: /.ado/templates/apple-tools-setup.yml@self
-
   - task: CmdLine@2
     displayName: yarn install (local react-native-macos)
     inputs: