Fixes:
- solver: gracefully handle cache loading errors #1498
- remotecache: only visit each item once when walking results #1577
- cache: avoid possible nil dereference on error handling #1511
- contenthash: allow security.capability in cache checksum #1526
- contenthash: treat unix sockets as regular files #1581
- push: fix race condition on pushing the same layers in parallel #1548
- inline cache: fix handling of duplicate blobs in same image #1568
- gateway: fix metadata getting lost on subsolve in external frontend #1449
- filesync: avoid ignoring close error #1478
- runc: update runc binary to v1.0.0-rc91 #1553
- buildctl-daemonless: allow max retries on socket connect for buildctl #1493
- buildctl-daemonless: fix shell args expansion #1504
- buildctl-daemonless: show log on startup timeout #1565