fix cluster label section to external_label

Package Merge Request

Package Changes

Moves the cluster label from a relabel job to the external_labels field

Package MR

N/A

For Issue

Closes big-bang/product/packages/promtail#56 (closed)

Upgrade Notices

N/A

changed milestone to %2.31.0

added kindenhancement priority3 promtail statusreview teamObservability labels

requested review from @michaelmartin, @chris.oconnell, and @andrewshoell

assigned to @jimmyungerman

added debug label

requested review from @mike.knight

approved this merge request

merged

mentioned in commit fe6e1fce

mentioned in merge request big-bang/customers/template!93 (merged)