khal list should stream events

[WhyNotHugo]

Describe the bug

I want to run khal --color list now 2026-01-01 | less and be able to scroll down to see events in future.

Expected behavior

khal should print events one-per-line, one line at a time. less can then show output it is printed. Because less will block khal's stdout, khal won't waste time generating events which are never scrolled into view.

Actual behaviour

khal blocks generating its entire output before printing. khal list now 2026-01-01 takes 1550ms to run. less wont show any output until those 1550ms transpire.

Version

khal, version 0.11.3

[WhyNotHugo]

This is also an issue with the jsonl output.