FIX:Fix test compatible with python 3.12

[TNA-Allan]

Ticket URL: NA

About these changes

• issue running tests says

ERROR: test_no_links (etna.ciim.tests.test_utils.TestResolveLinks.test_no_links)
----------------------------------------------------------------------
Traceback (most recent call last):
  File "/app/etna/ciim/tests/test_utils.py", line 127, in test_no_links
    self.assertEquals("<span/>", stripped_markup)
    ^^^^^^^^^^^^^^^^^
AttributeError: 'TestResolveLinks' object has no attribute 'assertEquals'. Did you mean: 'assertEqual'?

FAILED (errors=38, skipped=37)

• update assertEquals to assertEqual that is compatible with python 3.12

How to check these changes

Run test locally should not throw failures

----------------------------------------------------------------------
Ran 476 tests in 18.196s

OK (skipped=37)

Before assigning to reviewer, please make sure you have

• Checked things thoroughly before handing over to reviewer
• Checked PR title starts with ticket number as per project conventions to help us keep track of changes
• Ensured that PR includes only commits relevant to the ticket
• Waited for all CI jobs to pass before requesting a review
• Added/updated tests and documentation where relevant

Merging PR guidance

Follow docs\developer-guide\contributing.md

Deployment guidance

Follow docs\infra\environments.md

[Firdaussi]

Yep, that looks good. Worked fine on my build.