release: sourcegraph@3.43.0

Created by: coury-clark

This pull request is part of the Sourcegraph 3.43.0 release.

• Release batch change
• Tracking issue

Test plan

CI checks in this repository should pass, and a manual review should confirm if the generated changes are correct.

Additional changes required

These steps must be completed before this PR can be merged, unless otherwise stated. Push any required changes directly to this PR branch.

• Ensure all other pull requests in the batch change have been merged
• Run yarn run release release:finalize to generate the tags required. CI will not pass until this command is run.
• Re-run the build on this branch (using either sg ci build --wait or the Buildkite UI) and merge when the build passes.

cc @coury-clark