Clean old deployment directories

[nikoshell]

Fix #1300

cd $(RELEASES_DIR) && \
ls -1dt */ |                         # list dirs by modification time
grep -v "^current/?$$" |             # skip the 'current' symlink
grep -v "^$(TIMESTAMP)/$$" |         # skip the one we just deployed
tail -n +4 |                         # keep the latest 3
xargs -r echo rm -rf                 # delete the rest (dry-mode with echo)

with "echo" in the command it's dry-mode

example output

[europython-society]

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last update	2025-06-26T21:39:57.742Z