Actions: Add apt-get update for module tests

Author: simmsa

.github/workflows/main.yml

@@ -583,7 +583,10 @@ jobs:
 
       - name: Install system dependencies
         if: matrix.module != 'river' || matrix.module != 'power' || matrix.module != 'utils' || matrix.module != 'loads'
-        run: sudo apt-get install -y libhdf5-dev libnetcdf-dev
+        run: |
+          # Update apt-get cache
+          sudo apt-get update
+          sudo apt-get install -y libhdf5-dev libnetcdf-dev
 
       - name: Install MHKiT with optional dependency
         run: |