Fix GitHub action to only build select packages

The directory ./templates contains `.go` files but is not meant to be a go package.

.github/workflows/go.yml

@@ -20,10 +20,7 @@ jobs:
       with:
         go-version: '1.20'
 
-    - name: Build
-      run: go build -v ./...
-
-    - name: Test
+    - name: Build and test
       run: sh ./test.sh
 
     - name: Upload coverage data