Update trainee program date to March 16, 2026

Author: davidlange6

pages/index.html

@@ -17,7 +17,7 @@ <h4>Research Software Collaborations in Physics</h4>
 
 {% capture irishead %}
 
-**March 17, 2025: [2025 Trainee program is looking for students and mentors](https://research-software-collaborations.org/trainee_program.html)
+**March 16, 2026: [2026 Trainee program is looking for students and mentors](https://research-software-collaborations.org/trainee_program.html)
 
 
 HSF-India is a US National Science Foundation (NSF) funded project