slack file upload depreciation March 11, 2025

[tmorrell]

Slack will be depreciating the file upload call

pubarchiver/scripts/helpers.sh

Line 93 in edb545c

run_slack file upload --channels $SLACK_CHANNEL --file $log \

used in https://github.com/rockymadden/slack-cli on March 11, 2025. The slack-cli project seems to be abandoned, so we should figure out another way to send content to Slack.