Merge #20106: cirrus: Use kvm to avoid spurious CI failures in the de…

…fault virtualization cluster

faf2999 cirrus: Use kvm to avoid spurious CI failures in the default virtualization cluster (MarcoFalke)

Pull request description:

  Try to fix #20093

ACKs for top commit:
  practicalswift:
    ACK faf2999
  hebasto:
    ACK faf2999, the related doc:

Tree-SHA512: 156aa2ce5a5dde11570f7f90f9d51be540a5469f090033ab6f337b2c46347741469e109f9566f4b7c424339483d61192b91102021f5db38823ce4cf4428e5671

.cirrus.yml

@@ -6,6 +6,7 @@ container:
   # Each project has 16 CPU in total, assign 2 to each container, so that 8 tasks run in parallel
   cpu: 2
   memory: 8G  # Set to 8GB to avoid OOM. https://cirrus-ci.org/guide/linux/#linux-containers
+  kvm: true  # Use kvm to avoid spurious CI failures in the default virtualization cluster, see https://github.com/bitcoin/bitcoin/issues/20093
 env:
   PACKAGE_MANAGER_INSTALL : "apt-get update && apt-get install -y"
   MAKEJOBS: "-j4"