mattermost-load-test-ng-v1.19.0

What's Changed

• Update postgres client by @streamer45 in #755
• Bump version strings in master by @agarciamontoro in #757
• Update retransmission threshold by @agnivade in #760
• Update coverage frequency docs by @agarciamontoro in #761
• MM-59319: Allow opensearch installations to be created by @agnivade in #763
• Allow 0 shard replicas by @agarciamontoro in #764
• MM-59316: Remove cloudwatch log policy by @agarciamontoro in #762
• Improvements from Redis investigation by @agnivade in #765
• Bump version to v1.19.0-rc1 by @agarciamontoro in #766
• Cherry-pick #768 by @agarciamontoro in #769
• Bump version to v1.19.0-rc2 by @agarciamontoro in #771
• Bump version to v1.19.0 by @agarciamontoro in #773

Full Changelog: v1.18.0...v1.19.0