fix contributors

CONTRIBUTORS.yaml

@@ -1008,7 +1008,7 @@ kenza12:
 
 kellsnow:
     name: Kellie Snow
-    joined: 03-2024
+    joined: 2024-03
 
 khanteymoori:
     name: Alireza Khanteymoori
@@ -1028,7 +1028,7 @@ khaled196:
 khens:
     github: false
     name: Korneel Hens
-    joined: 03-2024
+    joined: 2024-03
 kinow:
     name: Bruno P. Kinoshita
     joined: 2023-04
@@ -1076,7 +1076,7 @@ Lain-inrae:
 
 lcooper:
     name: Laura Cooper
-    joined: 03-2024
+    joined: 2024-03
     github: false
 
 lamouresparus:
@@ -1564,7 +1564,7 @@ pravs3683:
 
 proccaserra:
     name: Philippe Rocca-Serra
-    joined: 03-2024
+    joined: 2024-03
     orcid: 0000-0001-9853-5668
     elixir_node: uk
 
@@ -1669,7 +1669,7 @@ saritadc:
 
 saskia-lawson-tovey:
     name: Saskia Lawson-Tovey
-    joined: 03-2024
+    joined: 2024-03
     orcid: 0000-0002-8611-162X
 
 sbenateau:
@@ -1732,7 +1732,7 @@ simleo:
 
 sitjart:
     name: Xenia Perez Sitja
-    joined: 03-2024
+    joined: 2024-03
     orcid: 0000-0002-7166-0183
     elixir_node: uk