v0.4.1-rc.1

Changelog

• 25cfb20 cue/cuecontext: allow concurrent use
• 79303b6 doc: ensure all min Go versions refer to 1.16
• 8a40ef0 gitiles: change logo from SVG to PNG
• 28b4257 gitiles: customize navigation bar

Docker images

• docker pull docker.io/cuelang/cue:0.4.1-rc.1

Full Changelog: v0.4.1-beta.6...v0.4.1-rc.1