Hmm, I wonder how the voice assistant component became a mandatory part of HA first start setup. This happened even retrospectively for HA 2025.1.4 on Bullseye, so must have happened somehow with a new release of a non-core component which is compatible, hence installed on HA 2025.1.4 as well.
However, fix is here: dietpi-software: Home Assistant: add missing dependency · MichaIng/DietPi@638b5ef · GitHub
pyspeex-noise belongs to pymicro-vad, sort of, same developers, same version strings.