Remove Semester 2 2026 sign-up link from students.md

Removed the sign-up link for Semester 2 2026 updates.

Author: rowlandm

students.md

@@ -22,12 +22,6 @@ Please note that applications for the Summer 2025 / 2026 intake have now closed.
 
 Here are some of the [recurring student intern projects and new projects we are working on](project-wikis).
 
-<a href="https://forms.office.com/Pages/ResponsePage.aspx?id=4nJ8qs_FQEqiKqWFwEygfHucYnIbkjZJm7W73SM5JMBUN1lEOTNXWEI2WjI2OTRDV1E4MjlOSzNQNy4u" 
-   style="color: white; background-color: #2372b9; margin: 0.5em; padding: 0.25em 1em; border-radius: 6px; box-shadow: 3px 3px 3px rgba(0,0,0,0.2); text-decoration: none; float: left; width: 30%; margin-left: 21%; margin-bottom: 24px; text-align: center;">
-   Sign up for Semester 2 2026 updates
-</a>
-<div style="clear:both"></div>
-
 We have had 251 interns through the program since Semester 2, 2021 who have provided over 24 person years of effort to help us uncover and document complexity early in over 80 intern projects.
 
 Out of the 16 anonymous reviews that have been given by students as at 4th of June 2025, our internships have been rated a 4.6 out of 5.