[8.14] [ci] Use org wide PR comment bot (elastic#187354) (elastic#187377

)

# Backport

This will backport the following commits from `main` to `8.14`:
- [[ci] Use org wide PR comment bot
(elastic#187354)](elastic#187354)

<!--- Backport version: 9.4.3 -->

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

<!--BACKPORT
[{"author":{"name":"Jon","email":"[email protected]"},"sourceCommit":{"committedDate":"2024-07-02T15:03:58Z","message":"[ci]
Use org wide PR comment bot
(elastic#187354)","sha":"5b0dc5faeb5c0b5092cea98f76a16ff2b55acf71","branchLabelMapping":{"^v8.15.0$":"main","^v(\\d+).(\\d+).\\d+$":"$1.$2"}},"sourcePullRequest":{"labels":["Team:Operations","release_note:skip","backport:all-open","v8.15.0"],"title":"[ci]
Use org wide PR comment
bot","number":187354,"url":"https://github.com/elastic/kibana/pull/187354","mergeCommit":{"message":"[ci]
Use org wide PR comment bot
(elastic#187354)","sha":"5b0dc5faeb5c0b5092cea98f76a16ff2b55acf71"}},"sourceBranch":"main","suggestedTargetBranches":[],"targetPullRequestStates":[{"branch":"main","label":"v8.15.0","branchLabelMappingKey":"^v8.15.0$","isSourceBranch":true,"state":"MERGED","url":"https://github.com/elastic/kibana/pull/187354","number":187354,"mergeCommit":{"message":"[ci]
Use org wide PR comment bot
(elastic#187354)","sha":"5b0dc5faeb5c0b5092cea98f76a16ff2b55acf71"}}]}]
BACKPORT-->

Co-authored-by: Jon <[email protected]>

.buildkite/pipeline-resource-definitions/kibana-pr.yml

@@ -19,7 +19,7 @@ spec:
       description: Runs manually for pull requests
     spec:
       env:
-        PR_COMMENTS_ENABLED: 'true'
+        ELASTIC_PR_COMMENTS_ENABLED: 'true'
         GITHUB_BUILD_COMMIT_STATUS_ENABLED: 'true'
         GITHUB_BUILD_COMMIT_STATUS_CONTEXT: kibana-ci
         GITHUB_STEP_COMMIT_STATUS_ENABLED: 'true'

.buildkite/pipeline-utils/test-failures/annotate.ts

@@ -170,7 +170,7 @@ export const annotateTestFailures = async () => {
 
   buildkite.setAnnotation('test_failures', 'error', getAnnotation(failures, failureHtmlArtifacts));
 
-  if (process.env.PR_COMMENTS_ENABLED === 'true') {
+  if (process.env.ELASTIC_PR_COMMENTS_ENABLED === 'true') {
     buildkite.setMetadata(
       'pr_comment:test_failures:body',
       getPrComment(failures, failureHtmlArtifacts)