[8.19] [ci] Disable composite uploads (#271521) (#271588)

# Backport

This will backport the following commits from `main` to `8.19`:
- [[ci] Disable composite uploads
(#271521)](#271521)

<!--- Backport version: 9.6.6 -->

### Questions ?
Please refer to the [Backport tool
documentation](https://github.com/sorenlouv/backport)

<!--BACKPORT
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Disable composite uploads (#271521)\n\nCurrently we're running multiple
composite uploads in parallel. This can\noccasionally cause
issues:\n[example](https://buildkite.com/elastic/kibana-pull-request/builds/448905#019e69bd-ca57-434f-ae87-8a80bab26b53/L2173).\n\nThis
disables composite
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Disable composite
uploads","number":271521,"url":"https://github.com/elastic/kibana/pull/271521","mergeCommit":{"message":"[ci]
Disable composite uploads (#271521)\n\nCurrently we're running multiple
composite uploads in parallel. This can\noccasionally cause
issues:\n[example](https://buildkite.com/elastic/kibana-pull-request/builds/448905#019e69bd-ca57-434f-ae87-8a80bab26b53/L2173).\n\nThis
disables composite
uploads.","sha":"120c2cfe73b85005302b936eb0582116bb6a2844"}},"sourceBranch":"main","suggestedTargetBranches":[],"targetPullRequestStates":[{"branch":"main","label":"v9.5.0","branchLabelMappingKey":"^v9.5.0$","isSourceBranch":true,"state":"MERGED","url":"https://github.com/elastic/kibana/pull/271521","number":271521,"mergeCommit":{"message":"[ci]
Disable composite uploads (#271521)\n\nCurrently we're running multiple
composite uploads in parallel. This can\noccasionally cause
issues:\n[example](https://buildkite.com/elastic/kibana-pull-request/builds/448905#019e69bd-ca57-434f-ae87-8a80bab26b53/L2173).\n\nThis
disables composite
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BACKPORT-->

Co-authored-by: Jon <jon@elastic.co>

Author: kibanamachine

.buildkite/scripts/common/util.sh

@@ -218,7 +218,9 @@ upload_tmp_artifact() {
   "${SCRIPTS_COMMON_DIR}/activate_service_account.sh" "kibana-ci-artifacts-${GCS_CI_ARTIFACT_REGIONS[0]}"
 
   printf '%s\n' "${GCS_CI_ARTIFACT_REGIONS[@]}" | xargs -P 0 -I{} \
-    gcloud storage cp "$local_path" "gs://kibana-ci-artifacts-{}/tmp/builds/${build_id}/${artifact_name}"
+    env CLOUDSDK_STORAGE_PARALLEL_COMPOSITE_UPLOAD_ENABLED=False gcloud storage cp \
+      "$local_path" \
+      "gs://kibana-ci-artifacts-{}/tmp/builds/${build_id}/${artifact_name}"
 }
 
 print_if_dry_run() {