Update docs/guides/gb2025.md

Author: msimberg

docs/guides/gb2025.md

@@ -55,7 +55,7 @@ Your data sets from Daint are available on Santis
 
 Santis uses low noise mode, which reserves one core per Grace-Hopper module (i.e. per 72 cores) for system processes.
 This mode is intended to reduce performance variability caused by system processes interfering with application threads and processes.
-This means that that SLURM job scripts must be updated to account for the reserved cores.
+This means that SLURM job scripts must be updated to account for the reserved cores.
 
 ### SLURM