oppia: [Blocked on #18211] [BUG]: Unexpected error on using tab RTE component or collapsible RTE component empty

Describe the bug

When using tab interaction, if the new tab is added it can be saved empty but when we try to save the content it produces the unexpected error.

ERROR:root:Exception raised at http://localhost:8181/createhandler/autosave_draft/Ap35HNgkJ2ga: No collapsible content is present inside the tag.
Traceback (most recent call last):
  File "/home/hardik/opensource/oppia/core/controllers/editor.py", line 1478, in put
    exp_services.create_or_update_draft(
  File "/home/hardik/opensource/oppia/core/domain/exp_services.py", line 3096, in create_or_update_draft
    updated_exploration = apply_change_list(exp_id, change_list)
  File "/home/hardik/opensource/oppia/core/domain/exp_services.py", line 877, in apply_change_list
    raise e
  File "/home/hardik/opensource/oppia/core/domain/exp_services.py", line 537, in apply_change_list
    content.validate()
  File "/home/hardik/opensource/oppia/core/domain/state_domain.py", line 3491, in validate
    html_cleaner.validate_tabs_and_collapsible_rte_tags(self.html)
  File "/home/hardik/opensource/oppia/core/domain/html_cleaner.py", line 595, in validate_tabs_and_collapsible_rte_tags
    raise utils.ValidationError(
core.utils.ValidationError: No collapsible content is present inside the tag.

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File "/tmp/tmpUThEfc/lib/python3.8/site-packages/webapp2.py", line 604, in dispatch
    return method(*args, **kwargs)
  File "/home/hardik/opensource/oppia/core/controllers/acl_decorators.py", line 2134, in test_can_save
    return handler(self, exploration_id, **kwargs)
  File "/home/hardik/opensource/oppia/core/controllers/editor.py", line 1487, in put
    raise self.InvalidInputException(e)
core.controllers.base.UserFacingExceptions.InvalidInputException: No collapsible content is present inside the tag.
ERROR:root:Exception raised: No collapsible content is present inside the tag.
Traceback (most recent call last):
  File "/home/hardik/opensource/oppia/core/controllers/editor.py", line 1478, in put
    exp_services.create_or_update_draft(
  File "/home/hardik/opensource/oppia/core/domain/exp_services.py", line 3096, in create_or_update_draft
    updated_exploration = apply_change_list(exp_id, change_list)
  File "/home/hardik/opensource/oppia/core/domain/exp_services.py", line 877, in apply_change_list
    raise e
  File "/home/hardik/opensource/oppia/core/domain/exp_services.py", line 537, in apply_change_list
    content.validate()
  File "/home/hardik/opensource/oppia/core/domain/state_domain.py", line 3491, in validate
    html_cleaner.validate_tabs_and_collapsible_rte_tags(self.html)
  File "/home/hardik/opensource/oppia/core/domain/html_cleaner.py", line 595, in validate_tabs_and_collapsible_rte_tags
    raise utils.ValidationError(
core.utils.ValidationError: No collapsible content is present inside the tag.

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File "/tmp/tmpUThEfc/lib/python3.8/site-packages/webapp2.py", line 604, in dispatch
    return method(*args, **kwargs)
  File "/home/hardik/opensource/oppia/core/controllers/acl_decorators.py", line 2134, in test_can_save
    return handler(self, exploration_id, **kwargs)
  File "/home/hardik/opensource/oppia/core/controllers/editor.py", line 1487, in put
    raise self.InvalidInputException(e)
core.controllers.base.UserFacingExceptions.InvalidInputException: No collapsible content is present inside the tag.

URL of the page where the issue is observed.

N/A

Steps To Reproduce

1. Visit the Exploration Editor in creator dashboard
2. Add tab interaction with adding a third tab empty

Expected Behavior

It should handle this error by putting a check for empty content in tab interaction N/A

Steps To Reproduce

1. Visit the Exploration Editor in creator dashboard
2. Add tab interaction as showed in the video

Expected Behavior

It should handle this error by putting a check for empty content in tab interaction

Screenshots/Videos

https://github.com/oppia/oppia/assets/135348086/049c3b02-b85f-4123-9883-70427fd551bc

What device are you using?

Desktop

Operating System

Linux

What browsers are you seeing the problem on?

Chrome

Browser version

No response

Additional context

No response

Tips for developers

Before addressing the bug, please identify which PR caused the issue (you can follow the steps here). If you identify the PR, comment on the issue with a link to it. If not, mention the commit hash of the oldest commit you saw the bug on (and the month and year it was made in).

Also, if this is your first issue, please make sure to follow https://github.com/oppia/oppia/wiki/Contributing-code-to-Oppia#choosing-a-good-first-issue and https://github.com/oppia/oppia/wiki/Contributing-code-to-Oppia#setting-things-up before claiming it. Thanks!