fix(capd): remove hack for btrfs/zfs support

Support for btrfs/zfs was upstreamed to kind in kubernetes-sigs/kind#1464, removing the need
for us to hack support in ourselves.

Helps kubernetes-sigs#8317

test/infrastructure/container/docker.go

@@ -430,15 +430,6 @@ func (d *dockerRuntime) RunContainer(ctx context.Context, runConfig *RunContaine
 	}
 	containerConfig.Env = envVars
 
-	// handle Docker on Btrfs or ZFS
-	// https://github.com/kubernetes-sigs/kind/issues/1416#issuecomment-606514724
-	if d.mountDevMapper(info) {
-		runConfig.Mounts = append(runConfig.Mounts, Mount{
-			Source: "/dev/mapper",
-			Target: "/dev/mapper",
-		})
-	}
-
 	configureVolumes(runConfig, &containerConfig, &hostConfig)
 	configurePortMappings(runConfig.PortMappings, &containerConfig, &hostConfig)