Enable DRA for 8.14 on Buildkite (#39321)

This commit enables publishing of DRA artifacts via Buildkite on the `8.14` by switching
the DRY_RUN default to `true.

Additionally it backports the Jenkins changes brought in #39322 that actually disable the
corresponding builds on Jenkins -- this is not really needed as Jenkins reads its configuration only from `main`
but it's done for consistency.

Relates: elastic/ingest-dev#3095, #39322

.buildkite/scripts/dra.sh

@@ -1,21 +1,11 @@
 #!/usr/bin/env bash
 
-# TODO: uncomment out below when Jenkins packaging has been stopped
-# if [[ "$DRY_RUN" == "true" ]]; then
-#     echo "~~~ Running in dry-run mode -- will NOT publish artifacts"
-#     DRY_RUN="--dry-run"
-# else
-#     echo "~~~ Running in publish mode"
-#     DRY_RUN=""
-# fi
-
-# TODO: delete the conditional below (and replace it with the above, uncommented out, section) after Jenkins packaging has been stopped
-if [[ "$DRY_RUN" == "false" ]]; then
-    echo "~~~ Running in publish mode"
-    DRY_RUN=""
-else
+if [[ "$DRY_RUN" == "true" ]]; then
     echo "~~~ Running in dry-run mode -- will NOT publish artifacts"
     DRY_RUN="--dry-run"
+else
+    echo "~~~ Running in publish mode"
+    DRY_RUN=""
 fi
 
 set -euo pipefail

.ci/jobs/packaging.yml

@@ -14,7 +14,7 @@
           discover-pr-forks-trust: 'permission'
           discover-pr-origin: 'merge-current'
           discover-tags: true
-          head-filter-regex: '(main|7\.1[6789]|8\.\d+|PR-.*|v\d+\.\d+\.\d+)'
+          head-filter-regex: '(7\.1[6789]|8\.13|PR-.*|v8\.13\.\d+)'
           disable-pr-notifications: true
           notification-context: 'beats-packaging'
           repo: 'beats'
@@ -29,14 +29,11 @@
               ignore-tags-newer-than: 30
           - named-branches:
               - exact-name:
-                  name: 'main'
+                  name: '8.13'
                   case-sensitive: true
               - regex-name:
                   regex: '7\.1[6789]'
                   case-sensitive: true
-              - regex-name:
-                  regex: '8\.\d+'
-                  case-sensitive: true
           - change-request:
               ignore-target-only-changes: true
           clean:

.pre-commit-config.yaml

@@ -9,4 +9,3 @@ repos:
     hooks:
     -   id: check-jenkins-pipelines
         files: ^(.ci/(.*\.groovy|Jenkinsfile)|Jenkinsfile)$
-    -   id: check-jjbb