Is installing openjdk-21-jdk on Debian 12 from jdk.java.net .deb safe, if its openjdk-21 package looks not working on Debian tracker?

Because Java 25 LTS is coming soon (September 2025) and I've not even yet installed Java JDK 21 LTS (September 2023), I've attempted to do so with a sudo apt install openjdk-21-jdk on my Debian 12. But it failed with a package not found message. Its package isn't available yet on Debian 12: [openjdk-21](https://tracker.debian.org/pkg/openjdk-21) (except on sid). I'm considering downloading it from [https://jdk.java.net/archive/](https://jdk.java.net/archive/) as a tar.gz of 21.0.2 (build 21.0.2+13) version (at the cost of forgetting apt commands to handle Java, and writing on my agenda to check manually for updates there) But I'm fearing this: Won't the .deb included in this .tar.gz break my system if I attempt to install it, if the dedicated openjdk-21-jdk package for Debian 12 cannot be created for years?