tmp: add ppa:mir-team/dev to Debian Sid

It's for source-only Rust packages, so...

Author: Saviq

spread/sbuild/task.yaml

@@ -72,6 +72,11 @@ execute: |
         --extra-repository="deb http://ppa.launchpad.net/mir-team/dev/ubuntu ${RELEASE} main"
         --extra-repository-key=${SPREAD_PATH}/${SPREAD_TASK}/mir-team.asc
       )
+    elif [[ "${SPREAD_VARIANT}" == *"debian"*  ]]; then
+      SBUILD_OPTS+=(
+        --extra-repository="deb http://ppa.launchpad.net/mir-team/test/ubuntu resolute main"
+        --extra-repository-key=${SPREAD_PATH}/${SPREAD_TASK}/mir-team.asc
+      )
     fi
 
     # Cross building