Update CHANGELOG for 8.54.0

[ci skip]

CHANGELOG

 # Changelog for gitlab-workhorse
 
+## v8.54.0
+
+### Changed
+- Don't reject image scaling requests based on file extension/format mismatch
+  https://gitlab.com/gitlab-org/gitlab-workhorse/-/merge_requests/651
+
+### Other
+- Rework image scaler test suite
+  https://gitlab.com/gitlab-org/gitlab-workhorse/-/merge_requests/
+- Adjust image scaling latency buckets
+  https://gitlab.com/gitlab-org/gitlab-workhorse/-/merge_requests/643
+- Update raven-go and gocertifi packages
+  https://gitlab.com/gitlab-org/gitlab-workhorse/-/merge_requests/644
+- jaeger: limit operation cardinality by using route regex
+  https://gitlab.com/gitlab-org/gitlab-workhorse/-/merge_requests/648
+
+### Performance
+- Add support for conditional GETs for rescaled images
+  https://gitlab.com/gitlab-org/gitlab-workhorse/-/merge_requests/647
+
 ## v8.53.0
 
 ### Added

changelogs/unreleased/319-img-scaler-use-detected-file-format.yml

----
-title: Don't reject image scaling requests based on file extension/format mismatch
-merge_request: 651
-author:
-type: changed

changelogs/unreleased/jaeger-operation-cardinality.yml

----
-title: 'jaeger: limit operation cardinality by using route regex'
-merge_request: 648
-author:
-type: other

changelogs/unreleased/mk-adjust-image-scaler-latency-buckets.yml

----
-title: Adjust image scaling latency buckets
-merge_request: 643
-author:
-type: other

changelogs/unreleased/mk-image-resizer-conditional-get.yml

----
-title: Add support for conditional GETs for rescaled images
-merge_request: 647
-author:
-type: performance

changelogs/unreleased/mk-rework-image-scaler-tests.yml

----
-title: Rework image scaler test suite
-merge_request:
-author:
-type: other

changelogs/unreleased/sh-update-raven-go.yml

----
-title: Update raven-go and gocertifi packages
-merge_request: 644
-author:
-type: other