audio/carla: Update to 1.9.8

Additional changes:

• Added the py-sip dependency (thanks to the user Goran Mekić <meka@tilda.center> for notifying me)
• Added USES=shebangfix because it is needed now
• Added CONFLICTS_BUILD=rtaudio-* rtmidi-* because it is bundled with incompatible versions of both packages and the build picks the preinstalled headers/libs first
• Removed BSD=true per the hint from the upstream author

Submitted by: myself
Approved by: tcberner (mentor)
Differential Revision: D13794