test: Add retry on flaky tests

[ykim-akamai]

📝 Description

Following list of tests failed occasionally in recent builds, refer to TOD for details.

• test_lke_cluster_labels_and_taints
• test_get_sshkeys
• test_ssh_key_create
• test_image_create
• test_image_replication
• test_save_linode_noforce
• test_save_linode_force
• test_linode_resize

This PR uses existing pytest library called pytest-rerunfailures to rerun tests with delay. Flaky tests now can simply be marked with

@pytest.mark.flaky(reruns=3, reruns_delay=2)

✔️ How to Test

This retry logic can be tested with simply forcing one of the tests listed above to fail. (E.g. Insert assert False in top section of the test) then run that following test using command like below.

make TEST_CASE="test_lke_cluster_labels_and_taints -s" testint

Each retry should be marked with "R" in terminal

e.g.

python3 -m pytest test/integration/ -k test_lke_cluster_labels_and_taints 

platform darwin -- Python 3.10.14, pytest-8.1.1, pluggy-1.4.0
rootdir: /Users/ykim/linode/ykim/linode_api4-python
configfile: pyproject.toml
plugins: anyio-4.3.0, rerunfailures-14.0
collected 173 items / 172 deselected / 1 selected                                                                                                                                                                                                                                                                                                                                                                                    

test/integration/models/lke/test_lke.py 
R [100%]R [100%]R [100%]F [100%]

📷 Preview

If applicable, include a screenshot or code snippet of this change. Otherwise, please remove this section.

[lgarber-akamai]

Full suite run: https://github.com/linode/linode_api4-python/actions/runs/10943195884/job/30382021169

[lgarber-akamai]

The test failures in the linked suite run look unrelated and the relevant tests are passing on my end, nice work!

[zliang-akamai]

LGTM