fix error in linting workflow file

Author: francescodelduchetto

.github/workflows/ci.yml

@@ -101,9 +101,9 @@ jobs:
 
       - name: Static Analysis (Linting)
         run: |
-        pip install flake8
-        # E9,F63,F7,F82 flag fatal syntax errors and undefined names
-        flake8 ./backend --count --select=E9,F63,F7,F82 --show-source --statistics
+          pip install flake8
+          # E9,F63,F7,F82 flag fatal syntax errors and undefined names
+          flake8 ./backend --count --select=E9,F63,F7,F82 --show-source --statistics
       # just a placeholder for your tests. Implement your actual test commands here, e.g. "pytest ..."
       - name: Run tests with coverage
         run: |