Build with RGBDS 0.8.0, though it is not yet required

Author: Rangi42

.github/workflows/main.yml

@@ -16,7 +16,7 @@ jobs:
         uses: actions/checkout@master
         with:
           path: rgbds
-          ref: v0.7.0
+          ref: v0.8.0
           repository: gbdev/rgbds
 
       - name: Install rgbds