This appears to be a bug in libxmlb-dev, it's missing a dependency on libzstd-dev.
- Bug#1051294: fwupd: FTBFS: Run-time dependency xmlb fou... Sebastian Ramacher
- Bug#1051294: This appears t Mario Limonciello
This appears to be a bug in libxmlb-dev, it's missing a dependency on libzstd-dev.