Upgrade `elasticsearch` client, remove 7.x patch logics

[mashhurs]

Description

Upgrade elasticsearch client in 3.x and main active branches

• main:

  logstash-filter-elasticsearch/logstash-filter-elasticsearch.gemspec

  Line 24 in 6c9a505

  s.add_runtime_dependency 'elasticsearch', ">= 7.14.9", '< 9'

• 3.x -

  logstash-filter-elasticsearch/logstash-filter-elasticsearch.gemspec

  Line 24 in ca3bca2

  s.add_runtime_dependency 'elasticsearch', ">= 7.14.9", '< 9'

• remove/adapt patch logics if need - https://github.com/logstash-plugins/logstash-filter-elasticsearch/blob/main/lib/logstash/filters/elasticsearch/patches/_elasticsearch_transport_http_manticore.rb