feat: add a failing test fixture for linting

Author: iennae

.internal/tests/fixtures/test_fail.py

@@ -0,0 +1,11 @@
+# test_fail.py
+import sys  # Flake8 Error: 'sys' imported but unused
+import os
+
+def calculate_square (number): # Flake8 Error: extra space before opening parenthesis
+    
+    result=number*number # Flake8 Error: missing whitespace around operator '='
+    print('The result is: ' + str(result)) # Black will want to change single quotes to double quotes
+    return result 
+
+# Intentional trailing whitespace on the line below to trigger Flake8