Fix: Display correct author dates when birth/death years contain non-numeric characters

[SharkyBytes]

Closes #10352

Fix: Display correct author dates when birth/death years contain non-numeric characters

Technical

-> Updated the extract_year method in helpers.py to handle non-numeric characters in birth/death dates.
-> Modified the BookByline.html template to ensure proper display of dates, even when non-numeric characters (e.g., "19xx") are present.
-> Added an optional int_only parameter to the extract_year method to avoid breaking changes in other parts of the codebase.

Testing

-> Verify that the author's dates are displayed correctly without empty brackets.
-> Run the test suite to ensure no regressions:

Screenshot

What I changed -:

Stakeholders

@cdrini

[cdrini]

Awesome work @SharkyBytes ! A few pieces of feedback to make the logic a little clearer 👍

[SharkyBytes]

Hi @cdrini,
Just checking in— is there anything else I need to work on, or are you satisfied with the resolved changes? If any further adjustments are needed, please let me know, and I'll be happy to address them.

[cdrini]

Looks great! Made one small change to take advantage of the default return of extract_year being '', and tested on testing.openlibrary.org :

✅ Only has birth + inexact; has no birth or death year (eg)

✅ Has both birth/death (eg)