[CI] Fix hacky cargo-rpm usage
Cross compiling with
cargo-rpm is currently quite hacky:
[package.metadata.rpm] target_architecture = "armv7hl" [package.metadata.rpm.cargo] buildflags = ["--release"] target = "arm-unknown-linux-gnueabihf"
... these things should be inferred from cargo's
--target itself. Upstream issue: https://github.com/RustRPM/cargo-rpm/issues/47. This has quite some impact in