[CI] Add packaging step to integration matrix pipeline (#5168)

.buildkite/pipeline.integration-test-matrix.yml

@@ -5,9 +5,22 @@ env:
   VAULT_PATH: "kv/ci-shared/observability-ingest/cloud/gcp"
 
 steps:
+  - label: "Integration tests: packaging"
+    key: "package-it"
+    command: ".buildkite/scripts/steps/integration-package.sh"
+    artifact_paths:
+      - build/distributions/**
+    agents:
+      provider: "gcp"
+      machineType: "n1-standard-8"
+
   - label: "Integration test matrix"
     key: "integration-tests-matrix"
-    command: ".buildkite/scripts/steps/integration_tests.sh stateful integration:matrix"
+    depends_on: "package-it"
+    command: |
+      echo "~~~ Downloading artifacts"
+      buildkite-agent artifact download build/distributions/** . --step 'package-it'
+      .buildkite/scripts/steps/integration_tests.sh stateful integration:matrix
     artifact_paths:
       - "build/TEST-**"
       - "build/diagnostics/*"