v0.5.0-rc.1

Full release notes to follow in the final v0.5.0 release.

• internal/ci: move evict_caches to base by @myitcv in 584b21e
• internal/ci: remove mention of matrix and runner from base by @myitcv in 7c07680
• internal/ci: remove trybot from push branches by @myitcv in 9f3af8f
• internal/ci: refactor base caching pattern by @myitcv in 390bca5
• internal/ci: drop pullThroughProxy step by @myitcv in a14fbf4
• [release-branch.v0.5] internal/ci: bring inline with be0601b by @myitcv in f4d04a7
• internal/ci: bump pinned version of Go for releases by @mvdan in 374a2cc
• internal/core/adt: revert fix for 2209 by @mpvl in c0421b4
• internal/core/adt: fix possible infinte loop for API usage by @mpvl in 1ce9120
• internal/core/adt: fix regression in comparing to bottom by @mpvl in 87c79ef
• internal/core/adt: remove unnecessary check by @mpvl in 28321f6
• internal/core/adt: detect closed lists as fatal errors by @mpvl in 5d42c6c
• internal/core/adt: sharpen condition for scalar setting by @mpvl in 3ba76ba