[PSM Interop] Ignore DeprecationWarning: HTTPResponse.getheaders() (#34018)

Disables the warning produced by kubernetes/client/rest.py calling the
deprecated `urllib3.response.HTTPResponse.getheaders`,
`urllib3.response.HTTPResponse.getheader` methods:

```
venv-test/lib/python3.9/site-packages/kubernetes/client/rest.py:44: DeprecationWarning: HTTPResponse.getheaders() is deprecated and will be removed in urllib3 v2.1.0. Instead access HTTPResponse.headers directly.
  return self.urllib3_response.getheaders()
```

This issue introduced by openapi-generator, and solved in `v6.4.0`. To
fix the issue properly, kubernetes/python folks need to regenerate the
library using newer openapi-generator. The most recent release `v27.2.0`
still used openapi-generator
[`v4.3.0`](https://github.com/kubernetes-client/python/blob/v27.2.0/kubernetes/.openapi-generator/VERSION).
Since they release two times a year, and the 2 major version difference
of openapi-generator, the fix may take a while.

Created an issue in their repo:
https://github.com/kubernetes-client/python/issues/2101.

tools/run_tests/xds_k8s_test_driver/framework/infrastructure/k8s.py

@@ -20,6 +20,7 @@ import logging
 import pathlib
 import threading
 from typing import Any, Callable, List, Optional, Tuple
+import warnings
 
 from kubernetes import client
 from kubernetes import utils
@@ -105,6 +106,17 @@ class KubernetesApiManager:
         self.apps = client.AppsV1Api(self.client)
         self.core = client.CoreV1Api(self.client)
         self._apis = {self.apps, self.core}
+        # TODO(https://github.com/kubernetes-client/python/issues/2101): remove
+        #  when the issue is solved, and the kubernetes dependency is bumped.
+        warnings.filterwarnings(
+            "ignore",
+            category=DeprecationWarning,
+            module="kubernetes",
+            message=(
+                "HTTPResponse.getheaders?\\(\\) is deprecated"
+                " and will be removed in urllib3 v2.1.0."
+            ),
+        )
 
     @property
     def client(self) -> ApiClient: