[release] skip arm on 2.8 and earlier (#18705)

ci/split-release-job.yml

@@ -26,6 +26,21 @@ jobs:
     - template: bash-lib.yml
       parameters:
         var_name: bash-lib
+    - bash: |
+        set -euo pipefail
+        major=$(cat NIGHTLY_PREFIX | awk -F. '{print $1}')
+        minor=$(cat NIGHTLY_PREFIX | awk -F. '{print $2}')
+        setvar() {
+          echo "Setting '$1' to '$2'"
+          echo "##vso[task.setvariable variable=$1]$2"
+        }
+        if ([ "$(uname -m)" = "aarch64" ] || [ "$(uname -m)" = "arm64" ]) \
+          && ([ "$major" = "2" ] && [ "$minor" -lt "9" ]); then
+          setvar skip true
+        else
+          setvar skip false
+        fi
+      name: check-arm-needed
     - task: DownloadPipelineArtifact@0
       inputs:
         artifactName: linux-intel-release
@@ -35,7 +50,9 @@ jobs:
       inputs:
         artifactName: linux-arm-release
         targetPath: $(Build.StagingDirectory)/release-artifacts
-      condition: and(succeeded(), not(eq(variables['skip-github'], 'TRUE')))
+      condition: and(succeeded(),
+                     not(eq(variables.skip, 'true')),
+                     not(eq(variables['skip-github'], 'TRUE')))
     - task: DownloadPipelineArtifact@0
       inputs:
         artifactName: macos-release