Update and_gate.py

addressing issue TheAlgorithms#8656 by calling `test_and_gate()` , ensuring that all the assertions are verified before the actual output is printed.

Author: rohan472000

Diff for: boolean_algebra/and_gate.py

@@ -43,6 +43,7 @@ def test_and_gate() -> None:
 
 
 if __name__ == "__main__":
+    test_and_gate()
     print(and_gate(0, 0))
     print(and_gate(0, 1))
     print(and_gate(1, 1))