fix(handlers): clarify log message when registry is at max concurrent imports

See merge request !985

build: drop go 1.16 support

See merge request !981

docs: add changelog entry for S3 delete error checking fix (5aa89957)

See merge request !984

chore(datastore): expose CreateOrFind to the manifest store

See merge request !974

chore: log DB repository migration status for manifest uploads and downloads

See merge request !987

fix(datastore): race condition pushing two or more manifests by tag with the same digest

See merge request !966

feat!: remove htpasswd authentication

See merge request !963

build: cleanup makefile and use go run with version suffix

See merge request !988

fix(datastore): do not attempt to import non-distributable layers

See merge request gitlab-org/container-registry!997

test: run tests without --short flag on master branch

See merge request !990

fix(datastore): gracefully handle tags deleted between list and import

See merge request !993

fix(datastore): gracefully handle manifest broken link during imports

See merge request !994

fix(datastore): gracefully handle tags with broken links during imports

See merge request !995

## [3.39.3](v3.39.2-gitlab...v3.39.3-gitlab) (2022-05-02)

### Bug Fixes

* **datastore:** do not attempt to import non-distributable layers ([74494287](74494287))
* **datastore:** gracefully handle manifest broken link during imports ([32bc9924](32bc9924))
* **datastore:** gracefully handle tags deleted between list and import ([1c1a6d6f](1c1a6d6f))
* **datastore:** gracefully handle tags with broken links during imports ([2b53c0d3](2b53c0d3))
* **datastore:** race condition pushing two or more manifests by tag with the same digest ([54accd53](54accd53))
* **handlers:** clarify log message when registry is at max concurrent imports ([aa3825c6](aa3825c6))