Remove Fossdem and add birmingHack redirects (#876)

Signed-off-by: Bros112 <91689166+Bros112@users.noreply.github.com>

Author: Bros112

_redirects

@@ -84,9 +84,6 @@
 /hoodie /hoodies
 /hoody /hoodies
 
-# FOSDEM 2026
-/fosdem https://docs.google.com/forms/d/e/1FAIpQLSddMCMSyMuLTGfM5UspCmcJUddcmFmcl3F3zxFE1XBy9VGZeA/viewform?usp=publish-editor
-
 # 2024 Welcome
 /welcome https://www.youtube.com/watch?v=gJcnfB2ep7E
 
@@ -101,3 +98,6 @@
 
 /bletchley https://www.guildofstudents.com/events/6531/12107/
 /bletchley-park /bletchley
+
+# Hackathons
+/birminghack https://birminghack.com/