Log Message:
Update devel/fossil to 2.20

Changes for version 2.20 (2022-11-16)

 * Added the chat-timeline-user setting. If it is not an empty string, then any
   changes that would appear on the timeline are announced in the chat room.
 * The /unsubscribe page now requests confirmation. Email notifications now
   contain only an "Unsubscribe" link, and not a link to subscription
   management.
 * Added the "fossil branch lsh" subcommand to list the most recently \ 
modified
   branches.
 * More elements of the /info page are now inside of an accordion.
 * Replace the --dryrun flag with --dry-run in all commands which still used
   the former name, for consistency.
 * Rebuilt the stock Dockerfile to create a "from scratch" Busybox based
   container image via an Alpine Linux intermediary
 * Added a new document describing how to customize, use, and run that
   container.
 * Added "by hour of day" report to the /reports page.
 * Improved correctness, usability, and efficiency for the case when values in
   a TICKET's column tend to be long and volatile.
 * Fixed a bug introduced in 2.17 that prevented clone --unversioned from
   completing the retrieval of UV files from the remote repo. While fixing
   that, enabled UV tracing output with clone --unversioned --verbose, making
   it consonant with uv sync --verbose.