chore(deps): update kibana-openapi-spec digest to 6a867d8 (#1435)

* chore(deps): update kibana-openapi-spec digest to 6a867d8

* Fixup build

---------

Co-authored-by: elastic-renovate-prod[bot] <174716857+elastic-renovate-prod[bot]@users.noreply.github.com>
Co-authored-by: Toby Brain <[email protected]>

Author: elastic-renovate-prod[bot]

generated/kbapi/Makefile

@@ -2,7 +2,7 @@
 SHELL := /bin/bash
 ROOT_DIR := $(shell dirname $(realpath $(firstword $(MAKEFILE_LIST))))
 
-github_ref ?= 96ffcd79c2227e2236811a820f456044b691b2a4
+github_ref ?= 6a867d8e589056123e9e08e61256f48f6edb092e
 oas_url    := https://raw.githubusercontent.com/elastic/kibana/$(github_ref)/oas_docs/output/kibana.yaml
 
 .PHONY: all