CI should use spago.dhall for the build

Author: jamesdbrock

.github/workflows/ci.yml

@@ -26,11 +26,11 @@ jobs:
             .spago
             output
 
-      - name: Install dependencies
-        run: spago -x spago-dev.dhall install
+      - name: Install dev dependencies
+        run: spago install
 
       - name: Build source
-        run: spago -x spago-dev.dhall build --no-install --purs-args '--censor-lib --strict --censor-codes='UserDefinedWarning''
+        run: spago build --no-install --purs-args '--censor-lib --strict --censor-codes='UserDefinedWarning''
 
       - name: Run tests
         run: spago -x spago-dev.dhall test --no-install