v2.15.7

Changes:

• e5d482c Bumping to version 2.15.7
• c6dcd8b Use DownloadPipelineArtifact@2. Refer to downloaded files in GithubRelease@0
• 0ba8683 Bumping to version 2.15.6
• 1d0dded Add PublishPipelineArtifact@1 task, refer to its files from release task

This list of changes was auto generated.