rptest: force cleaning of teleport data dir

[andrewhsu]

following on PR #16359, this PR fixes error in running ducktape tests on cloudv2:

...
  File "/home/ubuntu/redpanda/tests/rptest/clients/kubectl.py", line 271, in _setup_tbot
    shutil.rmtree(self.TELEPORT_DATA_DIR)
  File "/usr/lib/python3.10/shutil.py", line 715, in rmtree
    onerror(os.lstat, path, sys.exc_info())
  File "/usr/lib/python3.10/shutil.py", line 713, in rmtree
    orig_st = os.lstat(path)
FileNotFoundError: [Errno 2] No such file or directory: '/tmp/tbot-data'

by forcing deletion of the teleport data dir.

i validated this by running test without /tmp/tbot-data dir to simulate buildkite's scheduled job scenario:

ducktape \
  --debug \
  --globals=/home/ubuntu/redpanda/tests/globals.json \
  --cluster=ducktape.cluster.json.JsonCluster \
  --cluster-file=/home/ubuntu/redpanda/tests/cluster.json \
  tests/rptest/tests/services_self_test.py::SimpleSelfTest.test_cloud

output:

test_id:    rptest.tests.services_self_test.SimpleSelfTest.test_cloud
status:     PASS
run time:   54.107 seconds
----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
========================================================================================================================================================================================
SESSION REPORT (ALL TESTS)
ducktape version: 0.8.18
session_id:       2024-02-08--006
run time:         54.125 seconds
tests run:        1
passed:           1
flaky:            0
failed:           0
ignored:          0
opassed:          0
ofailed:          0
========================================================================================================================================================================================

Backports Required

• none - not a bug fix
• none - this is a backport
• none - issue does not exist in previous branches
• none - papercut/not impactful enough to backport
• v23.3.x
• v23.2.x
• v23.1.x

Release Notes

• none

[andrewhsu]

this pr is ready for review. i have example of successful test run in description. no need to wait for other tests in PR check to run to completion.

[savex]

lgtm

[vbotbuildovich]

ducktape was retried in https://buildkite.com/redpanda/redpanda/builds/44891#018d8995-09c8-4cbe-9edd-5827b35f9f6d

ducktape was retried in https://buildkite.com/redpanda/redpanda/builds/44891#018d89a6-74ac-40f5-8877-5c21bd01a607