[CI] Parallelize eslint to speed it up (#136972) (#137006)

(cherry picked from commit 20dec08bf1)

Co-authored-by: Brian Seeders <brian.seeders@elastic.co>

.buildkite/pipelines/on_merge.yml

@@ -65,9 +65,9 @@ steps:
   - command: .buildkite/scripts/steps/lint.sh
     label: 'Linting'
     agents:
-      queue: n2-2-spot
+      queue: n2-8-spot
     key: linting
-    timeout_in_minutes: 90
+    timeout_in_minutes: 60
     retry:
       automatic:
         - exit_status: '-1'

.buildkite/pipelines/pull_request/base.yml

@@ -31,9 +31,13 @@ steps:
   - command: .buildkite/scripts/steps/lint.sh
     label: 'Linting'
     agents:
-      queue: n2-2
+      queue: n2-8-spot
     key: linting
-    timeout_in_minutes: 90
+    timeout_in_minutes: 60
+    retry:
+      automatic:
+        - exit_status: '-1'
+          limit: 3
 
   - command: .buildkite/scripts/steps/lint_with_types.sh
     label: 'Linting (with types)'

.buildkite/scripts/steps/lint.sh

@@ -16,9 +16,9 @@ echo '--- Lint: eslint'
 # after possibly commiting fixed files to the repo
 set +e;
 if is_pr && ! is_auto_commit_disabled; then
-  node scripts/eslint --no-cache --fix
+  git ls-files | grep -E '\.(js|mjs|ts|tsx)$' | xargs -n 250 -P 6 node scripts/eslint --no-cache --fix
 else
-  node scripts/eslint --no-cache
+  git ls-files | grep -E '\.(js|mjs|ts|tsx)$' | xargs -n 250 -P 6 node scripts/eslint --no-cache
 fi
 
 eslint_exit=$?