Fix getopt parameters

The parameters passed to `getopt` have a few discrepancies which can cause unexpected behaviour depending on which args are passed. * **Long-format `--interval`, `--cycles` and `--packages-limit`:** Missing the `:` meant only the short options would receive the value * **Short `-d` and long-format `--devel` args**: Redundant `::` for a flag that takes no value (mostly harmless) The `-n`/`--notify` flag was also missing, which combined with `shift 2` meant a command like `waybar-updates -n -d` would eat the `-d`.