Remove dead plugins

[jakubvrana]

Please remove my plugin Aladin wind (windy-plugin-aladin). The data source is gone and it's not probable that it will be back.

Please also remove the plugin Paragliding flyability (windy-plugin-pg) which is not mine. Its data source is also gone, https://pg-api.ovh/ is not even in the DNS anymore. This plugin didn't work for long periods in the past. I've contacted the author several times which always helped only for a short time.