remove changelog entry that belongs in 8.7

Fixes elastic#34340

CHANGELOG.asciidoc

@@ -79,7 +79,6 @@ https://github.com/elastic/beats/compare/v8.5.3\...v8.6.0[View commits]
 *Affecting all Beats*
 
 - Add `http.pprof` config options for enabling block and mutex profiling. {issue}33572[33572] {pull}33576[33576]
-- Added append Processor which will append concrete values or values from a field to target. {issue}29934[29934] {pull}33364[33364]
 - Add `add_formatted_index` processor that allows the resulting index for an event to be changed based on content from the event. {pull}33800[33800]
 - deps: Updated to github.com/elastic/go-sysinfo v1.9.0. {pull}33864[33864]
 - Fix panic due to close of already closed channel during shutdown. {pull}33971[33971]