feat: stop VM as part of prepare.sh and remove redundand rm

Author: fkondej

custom-recipes/buildernet/mkosi/playground.yaml

@@ -33,7 +33,6 @@ recipe:
         env:
           BUILDERNET_IMAGE: ".flashbots-images/mkosi.output/buildernet-qemu_latest.qcow2"
         init:
-          - rm -rf .runtime/buildernet-vm.qcow2 || true
           - ./scripts/prepare.sh
         start: ./scripts/start.sh
         stop:

custom-recipes/buildernet/mkosi/scripts/prepare.sh

@@ -31,6 +31,9 @@ echo "prepare.sh: PROJECT_DIR=${PROJECT_DIR}"
 echo "prepare.sh: RUNTIME_DIR=${RUNTIME_DIR}"
 echo "prepare.sh: SOURCE=${SOURCE}"
 
+# Ensure the VM is stopped before replacing runtime files (PID file, disk images).
+"${SCRIPT_DIR}/stop.sh"
+
 rm -rf "${RUNTIME_DIR}"
 mkdir -p "${RUNTIME_DIR}"