Depend on specific minor version for dependencies inside the workspace

This changes dependencies between crates inside the pipewire-rs workspace to depend on a specific minor version (0.x) instead of only the major version (0), to ensure all crates have the same minor version when used from crates.io.

Previously, once could e.g. use pipewire 0.7 combined with libspa 0.6, which is incorrect and can lead to compilation failure.