fixes in spkg-configure.m4's

[dimpase]

This allows external flint 3.3.*, and fixes errors in spkg-configure.4 of roman_numerals_py

📝 Checklist

• The title is concise and informative.
• The description explains in detail what this PR is about.
• I have linked a relevant issue or discussion.
• I have created tests covering the changes.
• I have updated the documentation and checked the documentation preview.

⌛ Dependencies

[github-actions]

Documentation preview for this PR (built with commit 9bbf612; changes) is ready! 🎉
This preview will update shortly after each push to this PR.

[kiwifb]

Gosh, that was really me that made that "numerical" mistake. LGTM.

[kiwifb]

LGTM

[vbraun]

doc-html fails

[sagemath_doc_html-none] [spkg-install] [valuation]       File "/home/release/Sage/local/var/lib/sage/venv-python3.12.5/lib/python3.12/site-packages/sphinx/registry.py", line 544, in load_extension      
[sagemath_doc_html-none] [spkg-install] [valuation]         raise ExtensionError(                                                                                                                          
[sagemath_doc_html-none] [spkg-install] [valuation]     sphinx.errors.ExtensionError: Could not import extension sphinx.builders.latex (exception: No module named 'roman_numerals')                       

[dimpase]

@vbraun - can you provide top-level config.log for this run?

[dimpase]

unless roman_numerals is misdetected as available, it must be something else