chore(e2e): fix long filenames

[nevermarine]

Description

Fix "file name too long" error in e2e test dump functions by truncating long test names in generated filenames.

Why do we need it, and what problem does it solve?

E2e tests with deeply nested Describe/It blocks produce very long spec names. When these names are used verbatim in dump filenames (e.g. e2e_failed__<testname>__<namespace>__events.yaml), the resulting path exceeds the 255-byte filename limit on Linux filesystems (ext4/xfs), causing the dump to fail with file name too long.

Example failing filename:

e2e_failed__virtualmachineadditionalnetworkinterfaces_verifies_interface_name_persistence_after_removing_middle_clusternetwork_should_preserve_interface_name_after_removing_middle_clusternetwork_and_rebooting__v12n-e2e-vm-additional-network-2wqtt__events.yaml

What is the expected result?

1. Run an e2e test with a long nested spec name that previously failed to write dump files.
2. Verify dump files are written successfully with a truncated name containing ... in the middle.

Checklist

• The code is covered by unit tests.
• e2e tests passed.
• Documentation updated according to the changes.
• Changes were tested in the Kubernetes cluster manually.

[nevermarine]