chore(deps): update kibana-openapi-spec digest to a8b419c

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 ?= c99d51cf47585e53277092f7678cf33c8e279ef7
+github_ref ?= a8b419c3b324dba982b651d872f796e54c26a0dd
 oas_url    := https://raw.githubusercontent.com/elastic/kibana/$(github_ref)/oas_docs/output/kibana.yaml
 
 .PHONY: all