Use strict filetype checks when calling `gm`

See merge request gitlab-org/gitlab-workhorse!564

By default, `gm` will ignore file extensions and determine the correct decoder/encoder based on the file's magic bytes. This means that a file pretending to be something else based on its extension might get processed.

According to http://www.graphicsmagick.org/security.html it is recommended to specify the reader based on the expected type instead by prefixing the input file with `jpg:` or `png:` respectively.

Also started to add unit tests for the image resizer. Coverage still a
bit spotty.

Add logging for local LSIF ZIP caching

See merge request gitlab-org/gitlab-workhorse!579

[ci skip]

Support Azure custom storage domains

See merge request gitlab-org/gitlab-workhorse!593

Users of Azure Blob storage, particularly those using Azure China, Azure
Germany, or Azure Government, may need to customize the Azure
endpoint. To support this, we add a custom Azure URL opener that
supports the `domain` query parameter. This work has been submitted
upstream: https://github.com/google/go-cloud/pull/2851/files

Documentation for using Azure Blob storage:
https://gitlab.com/gitlab-org/gitlab/-/merge_requests/40693.

[ci skip]

Drop tests that check for log messages

See merge request gitlab-org/gitlab-workhorse!591

logrus starts a Goroutine to write messages to the output buffer, but
there is no way to flush these messages to ensure they are ready
(https://github.com/sirupsen/logrus/issues/435). To avoid race
conditions, drop these log checks from our tests.

Use maximum size to reject file upload as needed

See merge request gitlab-org/gitlab-workhorse!554

Eliminate unnecessary code in GoCloud test stubs

See merge request gitlab-org/gitlab-workhorse!590

This should eliminate a race condition that only occurred in the test
where multiple Goroutines attempt to write to the same value when
opening a bucket.

[ci skip]

Remove an in-memory buffer for LSIF transformation

Closes #284

See merge request gitlab-org/gitlab-workhorse!586

Support either local or remote upload but not both NO CHANGELOG

See merge request gitlab-org/gitlab-workhorse!574

Verify changelog file presence in CI NO CHANGELOG

Closes #273

See merge request gitlab-org/gitlab-workhorse!580

Fix race condition in httprs test

See merge request gitlab-org/gitlab-workhorse!584

Silence errors when Azure objects have aleady been deleted

See merge request gitlab-org/gitlab-workhorse!585

Fix objectstore.uploader.uploadError race

See merge request gitlab-org/gitlab-workhorse!583

In an normal upload flow, GitLab Rails will move a file to its final
destination and remove the temporary file. Workhorse issues a DELETE a
request to ensure this is cleaned up. Previously this was generating log
noise with every upload. Now only log an error message if there were
some error other than a 404.

The `So(server, ShouldNotBeNil)` call in the httprs test attempts to
print a string representation of the `server`, but this is racy because
the reconnection state is initialized in a
Goroutine. `httptest.NewServer()` always returns a valid value, so we
can drop this test.

Relates to https://gitlab.com/gitlab-org/gitlab-workhorse/-/issues/285

Tests: block until grpc server has stopped

Closes #281

See merge request gitlab-org/gitlab-workhorse!576

[ci skip]

Add additional logging for dynamic img resizing

See merge request gitlab-org/gitlab-workhorse!562

Fix semantical merge conflict (double import)

Closes #282

See merge request gitlab-org/gitlab-workhorse!577

Remove ProcessReferences flag

See merge request gitlab-org/gitlab-workhorse!543

Use testify/require in top level tests

See merge request gitlab-org/gitlab-workhorse!570