Fix empty title bug in CEURWS scraper

[faresh9]

Pull Request: Fixes #2395

Description

This pull request addresses the issue #2395, where the CEURWS scraper fails on an empty page name. The problem occurred when generating 'LAST P304 " "' for a specific URL (https://ceur-ws.org/Vol-3592/paper9.pdf). The expected behavior is that no page number should be generated in this case.

Caveats

• [ ] Breaking change (fix or feature that would cause existing functionality to not work as expected)
• [ ] This change requires a documentation update
  • [ ] I have made corresponding changes to the documentation
• [ ] This change requires new dependencies (None in this case)

If you make changes to the Python code

• [ ] My code passes the tox check; I can receive warnings about tests, documentation, or both

Testing

I tested the changes using the following steps:

1. Ran the command python3 -m scholia.scrape.ceurws proceedings-url-to-quickstatements https://ceur-ws.org/Vol-3592/paper9.pdf
2. Verified that the scraper now correctly handles the case of an empty page name
3. Checked the generated QuickStatements output to ensure no page number is incorrectly generated

Checklist

• [ ] I have commented my code, particularly in hard-to-understand areas
• [ ] My changes generate no new warnings
• [ ] I have not used code from external sources without attribution
• [ ] I have considered accessibility in my implementation
• [ ] There are no remaining debug statements (print, console.log, ...)

[fnielsen]

Could you rebase the branch and also fix the styling errors.

scholia/scrape/ceurws.py:133:1: W293 blank line contains whitespace
scholia/scrape/ceurws.py:135:80: E501 line too long (80 > 79 characters)
scholia/scrape/ceurws.py:177:1: E303 too many blank lines (3)
scholia/scrape/ceurws.py:385:1: E303 too many blank lines (3)

from flake8 scholia