fixed broken link to debian repos

fixed broken link to debian repos

Author: yamimaio

docs/mesa-upgrade/preflight-network.mdx

@@ -51,7 +51,7 @@ Available packages:
 
 Packages are available for **bookworm** and **noble** distributions.
 
-For detailed information about the Debian repository structure and configuration, please refer to the [Debian Repository documentation](https://apt.packages.minaprotocol.com/).
+For detailed information about the Debian repository structure and configuration, please refer to the [Debian Repository documentation](https://unstable.apt.packages.minaprotocol.com/).
 
 ## Connecting to the Network
 
@@ -245,7 +245,7 @@ In addition to the preflight release builds, nightly builds are also available f
 
 Nightly builds are available for both Debian packages and Docker images. These builds represent the latest development state and may be even more unstable than preflight releases.
 
-For more information about nightly builds and repository configuration, see the [Debian Repository documentation](https://apt.packages.minaprotocol.com/).
+For more information about nightly builds and repository configuration, see the [Debian Repository documentation](https://nightly.apt.packages.minaprotocol.com/).
 
 ## Verification