Update Images in integration tests

[yec-akamai]

📝 Description

Fixing integration test issues seeing in workflow: https://github.com/linode/linode_api4-python/actions/runs/25501433562/job/74835124597?pr=691

Update to use LTS images in test cases instead of invalid ones. Change the error code assertion to match the API change.

✔️ How to Test

make TEST_CASE=test_fails_to_create_image_with_non_existing_disk_id test-int
make TEST_CASE=test_linode_with_disk_encryption_disabled test-int
make TEST_CASE=test_disk_resize_and_duplicate test-int
make TEST_CASE=test_add_get_update_revoke_image_to_share_group test-int
make TEST_CASE=test_linode_create_disk test-int

[mawilk90]

I spotted that API returns [403] Unauthorized for disk_id = 111111 or 111112 or 111122 etc., but not for 122222 or 123456 (then the error is [404] Not Found). IMO, it's a bit strange and inconsistent. Does it make sense to use e.g. disk_id = 123456 to get [404] Not Found as before and instead of possible range of error codes (400 <= e.status < 500) and clarify this behaviour with API Team?

[yec-akamai]

Interesting, not sure why API returns inconsistent error message. I did the error code range check just to make sure it's a client error, so it can tolerates the small backend divergence like this.

[mawilk90]

I will ask API Team about that on Monday