switch back to using setup-aiken in workflow.

Author: KtorZ

.github/workflows/continuous-integration.yml

@@ -33,7 +33,9 @@ jobs:
       uses: actions/configure-pages@v2
 
     - name: 🧰 Install Aiken
-      run: cargo install --verbose --git https://github.com/aiken-lang/aiken.git
+      uses: aiken-lang/setup-aiken@v1
+      with:
+        version: v1.1.11
 
     - name: 📘 Generate documentation
       shell: bash