Mich selbst hatte es eiskalt erwischt: Ab August 2023 wurden per EU-Richtlinie T5 und T8 Leuchtstoffröhren verboten, Kompaktleuchten sind theoretisch bereits seit Februar 2023 verboten. In der Richtlinie ist eine Übergangszeit bis 2027 vorgesehen, ab dann sind diese Lampen nicht mehr erhältlich.
Nun sind unsere Vogellampen (mit UVB-Anteil) allesamt Leuchtstoffröhren, was also tun?
Store up
According to my research aquaterra24.de is currently the only shop still having T5 tubes with 54W (Arcadia Pro Kit) and 14W (Arcadia PureSun Midi) in stock (as of July 2023).
Switch to other lighting in the long term
There is currently one obstacle: The few LED bird lamps on the market (e.g. birdking or LEDx) only emit UVA light according to their own statement. Although this part of the light spectrum is very important for a bird's wellbeing and enables them to fully unfold their behavioural repertoire since birds see in this wave range. However, to produce vital vitamin D3, which is required for a healthy calcium metabolism, birds need UVB light. Established fluorescent bird lamps usually emit UVB light.
However, this is not as easily transferrable to LED technology since the wrong wave range can lead to vitamin D3 overdosing or burns of the eye. But LED bird lamps able to compete with fluorescent lights will surely soon enter the market.
Interim solution metal halide lamps
Until we have adequate LED bird lamps with UVB portion on the market, we can assure safe provision of UVB light for our birdies using metal halide lamps. Most of us will already have a sun spot with a metal halide lamp running (e.g. Lucky Reptile Bright Sun Bird). This could be combined with a UVA-emitting LED bird lamp and maybe run a little longer than the usual 1-2 hours a day.
Sunlight!
Especially during summer the opportunity to offer your birds real sunlight should not be neglected. You can e.g. put the cage on your balcony or in your garden or give your birds access to a wire-secured open window. That's for free and when it comes to lighting quality, nothing beats the original! 
Wenn ihr noch mehr zum Thema wissen wollt, empfehle ich euch unbedingt bei Licht im Terrarium vorbeizuschauen, der Blog der Physikerin Sarina Wunderlich ist ein absoluter Wissensschatz zum Thema Beleuchtung in der Reptilienhaltung (welche in den meisten Punkten auf Vögel übertragbar ist)!
Sources
https://www.watt24.com/ratgeber/leuchstoffroehren-verbot-2023-alles-was-du-wissen-musst/ (Stand 04.07.2023)
https://www.licht-im-terrarium.de/led/uvb (Stand 04.07.2023)
https://www.licht-im-terrarium.de/roehre/verbot (Stand 09.04.2024)
