[ci] Remove 9.0 branch (#238159)

## Summary

Removes 9.0 from CI since it is EoL

Author: Ikuni17

.buildkite/pipeline-resource-definitions/kibana-es-snapshots.yml

@@ -22,7 +22,7 @@ spec:
         SLACK_NOTIFICATIONS_CHANNEL: '#kibana-operations-alerts'
         ELASTIC_SLACK_NOTIFICATIONS_ENABLED: 'true'
       allow_rebuilds: true
-      branch_configuration: main 9.2 9.1 9.0 8.19 8.18 7.17
+      branch_configuration: main 9.2 9.1 8.19 8.18 7.17
       default_branch: main
       repository: elastic/kibana
       pipeline_file: .buildkite/pipelines/es_snapshots/build.yml
@@ -56,10 +56,6 @@ spec:
           cronline: 0 22 * * * America/New_York
           message: Daily build
           branch: '9.1'
-        Daily build (9.0):
-          cronline: 0 22 * * * America/New_York
-          message: Daily build
-          branch: '9.0'
         Daily build (8.19):
           cronline: 0 22 * * * America/New_York
           message: Daily build
@@ -99,7 +95,7 @@ spec:
         SLACK_NOTIFICATIONS_CHANNEL: '#kibana-operations-alerts'
         ELASTIC_SLACK_NOTIFICATIONS_ENABLED: 'true'
       allow_rebuilds: true
-      branch_configuration: main 9.2 9.1 9.0 8.19 8.18 7.17
+      branch_configuration: main 9.2 9.1 8.19 8.18 7.17
       default_branch: main
       repository: elastic/kibana
       pipeline_file: .buildkite/pipelines/es_snapshots/promote.yml
@@ -148,7 +144,7 @@ spec:
         ELASTIC_SLACK_NOTIFICATIONS_ENABLED: 'true'
         REPORT_FAILED_TESTS_TO_GITHUB: 'true'
       allow_rebuilds: true
-      branch_configuration: main 9.2 9.1 9.0 8.19 8.18 7.17
+      branch_configuration: main 9.2 9.1 8.19 8.18 7.17
       default_branch: main
       repository: elastic/kibana
       pipeline_file: .buildkite/pipelines/es_snapshots/verify.yml

.buildkite/pipeline-resource-definitions/kibana-on-merge-unsupported-ftrs.yml

@@ -23,7 +23,7 @@ spec:
         ELASTIC_SLACK_NOTIFICATIONS_ENABLED: 'true'
         SCOUT_REPORTER_ENABLED: 'true'
       allow_rebuilds: true
-      branch_configuration: main 9.2 9.1 9.0 8.19 8.18 7.17
+      branch_configuration: main 9.2 9.1 8.19 8.18 7.17
       default_branch: main
       repository: elastic/kibana
       pipeline_file: .buildkite/pipelines/on_merge_unsupported_ftrs.yml

.buildkite/pipeline-resource-definitions/kibana-on-merge.yml

@@ -26,7 +26,7 @@ spec:
         ELASTIC_SLACK_NOTIFICATIONS_ENABLED: 'true'
         SCOUT_REPORTER_ENABLED: 'true'
       allow_rebuilds: true
-      branch_configuration: main 9.2 9.1 9.0 8.19 8.18 7.17
+      branch_configuration: main 9.2 9.1 8.19 8.18 7.17
       default_branch: main
       repository: elastic/kibana
       pipeline_file: .buildkite/pipelines/on_merge.yml

renovate.json

@@ -19,7 +19,6 @@
     "main",
     "9.2",
     "9.1",
-    "9.0",
     "8.19",
     "8.18",
     "7.17"
@@ -4782,4 +4781,4 @@
       "datasourceTemplate": "docker"
     }
   ]
-}
+}

versions.json

@@ -16,11 +16,6 @@
       "branch": "9.1",
       "branchType": "release"
     },
-    {
-      "version": "9.0.9",
-      "branch": "9.0",
-      "branchType": "release"
-    },
     {
       "version": "8.19.6",
       "branch": "8.19",
@@ -37,4 +32,4 @@
       "branchType": "unmaintained"
     }
   ]
-}
+}