bug: long-term only mentors have apply button enabled during ad-hoc registration

[khairahscorner]

Bug Report

Describe the bug

The mentors page does not disable the "Apply for this mentor" button for mentors that are "Long-Term only" during ad-hoc cycles.

This is causing mentees to click the button for long-term only mentors, fill out the application form, only to get to the last page and not see the mentor in the available selections.

See thread: https://womencodingcommunity.slack.com/archives/C070RN4KNJC/p1783670523312289

To Reproduce

1. Go to https://mentorship.womencodingcommunity.com/mentorship/mentors when an ad-hoc cycle is open
2. Search for a long-term only mentor like "Anna Sementsova"
3. Button is enabled

Expected behavior

Button should be greyed out and not clickable for long-term only mentors during ad-hoc cycle registrations

Screenshots

Reproducibility

• The bug is reproducible consistently.
• The bug is sporadic or occurs randomly.

Impact

• The bug affects critical functionality.
• The bug affects minor functionality.
• The bug is a cosmetic issue.