treewide: make sure we use ruamel.yaml safe variant

we have multiple tests failing with the following:
```
>       self.stream.write(data)
E       ValueError: I/O operation on closed file.

../scylla/.local/lib/python3.12/site-packages/ruamel/yaml/emitter.py:1249: ValueError
```

seems like it start when we have calls from multiple thread that might be
updating the same files

trying to switch to the `safe` variant of ruamel.yaml seems to be helping
still not clear how we see it on some of the jobs, and not in all

ccmlib/cluster.py

@@ -15,7 +15,7 @@
 from ccmlib.common import logger
 from ccmlib.utils.version import parse_version
 
-yaml = YAML()
+yaml = YAML(typ='safe')
 yaml.default_flow_style = False
 
 class Cluster(object):

ccmlib/cluster_factory.py

@@ -10,7 +10,7 @@
 from ccmlib import repository
 from ccmlib.node import Node
 
-yaml = YAML()
+yaml = YAML(typ='safe')
 yaml.default_flow_style = False
 
 class ClusterFactory():

ccmlib/common.py

@@ -27,7 +27,7 @@
 from botocore import UNSIGNED
 from botocore.client import Config
 
-yaml = YAML()
+yaml = YAML(typ='safe')
 yaml.default_flow_style = False
 
 BIN_DIR = "bin"

ccmlib/dse_node.py

@@ -14,7 +14,7 @@
 from ccmlib import common
 from ccmlib.node import Node, NodeError
 
-yaml = YAML()
+yaml = YAML(typ='safe')
 yaml.default_flow_style = False
 
 

ccmlib/node.py

@@ -24,7 +24,7 @@
 from ccmlib.repository import setup
 from ccmlib.utils.version import parse_version
 
-yaml = YAML()
+yaml = YAML(typ='safe')
 yaml.default_flow_style = False
 
 class Status():

ccmlib/scylla_cluster.py

@@ -19,7 +19,7 @@
 
 SNITCH = 'org.apache.cassandra.locator.GossipingPropertyFileSnitch'
 
-yaml = YAML()
+yaml = YAML(typ='safe')
 yaml.default_flow_style = False
 
 class ScyllaCluster(Cluster):

ccmlib/scylla_docker_cluster.py

@@ -12,7 +12,7 @@
 
 LOGGER = logging.getLogger("ccm")
 
-yaml = YAML()
+yaml = YAML(typ='safe')
 yaml.default_flow_style = False
 
 class ScyllaDockerCluster(ScyllaCluster):

ccmlib/scylla_repository.py

@@ -23,7 +23,7 @@
 from ccmlib.utils.download import download_file, download_version_from_s3, get_url_hash, save_source_file
 from ccmlib.utils.version import parse_version
 
-yaml = YAML()
+yaml = YAML(typ='safe')
 yaml.default_flow_style = False
 
 

ccmlib/utils/sni_proxy.py

@@ -18,7 +18,7 @@
 
 logger = logging.getLogger(__name__)
 
-yaml = YAML()
+yaml = YAML(typ='safe')
 yaml.default_flow_style = False
 
 @contextmanager