Merge bitcoin#21445: cirrus: Use SSD cluster for speedup

fa21239 cirrus: Use SSD cluster for speedup (MarcoFalke)

Pull request description:

  Haven't tested, but this might be faster: https://twitter.com/fedor/status/1354505744293502980

ACKs for top commit:
  fanquake:
    ACK fa21239 - going to merge this now given there is a speedup, and it's enough to fix the fuzz task the is continually timing out.

Tree-SHA512: b24161ba2ed16fcf23ac6098100b04f7f6eb8936bb312a35fcd8e632568b877bfc09a1e522836fe298a2cd87a53a91e3b501a7f2e1c81cc0edb57c59aecffb0d

.cirrus.yml

@@ -28,7 +28,6 @@ global_task_template: &GLOBAL_TASK_TEMPLATE
     # 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
   ccache_cache:
     folder: "/tmp/ccache_dir"
   depends_built_cache: