Edit: Changed dietpi version referenced.
I have four Raspberry Pi 4bs running DietPi (10.6.2 Trixie) with all packages kept up to date.
On three of these Raspberry Pis, the update to RoonBridge 2.71 proceeded without issue.
However, on the 4th Raspberry Pi, post install the RoonBridge service failed to run. Looking at the logs, there was a dependency upon a missing library - libicu.
Installing libicu using “apt install libicu76” allowed me to successfully start the Roon Bridge service on this fourth Raspberry Pi.
Thus it appears that RoonBridge 2.71 introduces a new dependency that the update process does not accommodate.
F.Y.I. The Raspberry Pi in question runs a pretty minimal install of DietPi with, essentially, just RoonBridge , Samba client and server and Dietpi-dashboard installed. In addition it employs a USB connected DAC whereas the other three Raspberry Pis (with fairly similar minimal DietPi installs but with Samba client and server) all use an audio HAT of one type or another and all had libicu76 already installed - presumably because other installed packages had a dependency on libicu - which allowed the RoonBridge update to proceed without issue.
Edit: Note. The install of libicu76 was required because my Dietpi installation was based on Debian Trixie. libicu does not appear to be available for Bookworm and so, on Bookwork based installs, the libicu package to be installed is likely to be libicu74 rather than libicu76.
Edit: it turns out that I was wrong about the packages installed on the Dietpi system for which the Roon Bridge update failed. It did not have the Samba client or server installed,
