Less paper cuts

Hello Snapcrafters! The Snapcraft team is pleased to announce that version 3.6 is out.
This is a minor release to fix some outstanding issues and bring in an improvement to the ant plugin.

New in this release

Plugins

ant

It is now possible to specify the build file location with the ant-buildfile keyword.

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This is the full change set for 3.6

Sergio Schvezov

• docker images: update to be self contained (#2591)
• static: update to newer black (#2599)
• repo: set priority to critical for debs (LP: #1821313)

Kyle Fazzari

• docker images: use build stages and generate locale (#2588)
• {catkin,colcon} plugin: remove old ROS key (#2586)
• catkin plugin: check workspace for dependencies (#2585) (LP: #1832044)

Stefan Bodewig

• ant plugin: make build file location configurable (#2596)

Chris Patterson

• tools: add black snap to environment-setup.sh (#2595)

dependabot[bot]

• requirements: bump pyxdg from 0.25 to 0.26 (#2587)