Update CHANGELOG.md for 13.3.0+ee.0

[ci skip]

changelogs/unreleased/mk-usage-ping-node-utilization.yml

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-title: Record average CPU and memory utilization for Usage Ping
-merge_request: 4455
-author:
-type: other

changelogs/unreleased/pks-git-v2-28-0.yml

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-title: Upgrade Git to v2.28.0
-merge_request: 4483
-author:
-type: added

changelogs/unreleased/pokstad1-bump-grafana-dashabord-1-8-0.yml

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-title: Upgrade Grafana Dashboard to v1.8.0
-merge_request: 4409
-author:
-type: added

changelogs/unreleased/sh-support-aws-sse-config.yml

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-title: Add support for configuring AWS server side encryption
-merge_request: 4469
-author:
-type: added

changelogs/unreleased/sh-use-gcc-6-3-centos6.yml

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-title: Use gcc v6.3 for CentOS 6 to build Rails C extensions
-merge_request: 4466
-author:
-type: other

changelogs/unreleased/smh-remove-read-only-mode-config.yml

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-title: Remove read-only config toggle from Praefect
-merge_request: 4462
-author:
-type: changed

changelogs/unreleased/tw-update-default-terraform-remote-directory.yml

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-title: Use S3-compatible remote directory for Terraform state storage
-merge_request: 4412
-author:
-type: other

changelogs/unreleased/zj-update-defaults-praefect.yml

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-title: Update Praefect defaults
-merge_request: 4416
-author:
-type: changed