Remove step for iptables installation

Installation of iptables was implemented in environment preparation pipeline and tests
do not need to worry about it.
Removed conditions that were checking pytest mode vs robot mode, because we got rid of
robot tests in this branch of codebase.

Signed-off-by: Vladimir Domnich <v.domnich@yadro.com>

robot/resources/lib/python_keywords/epoch.py

@@ -1,6 +1,4 @@
 #!/usr/bin/python3.9
-import sys
-
 import allure
 from robot.api import logger
 from robot.api.deco import keyword
@@ -40,12 +38,11 @@ def tick_epoch():
             err = str(exc)
             raise RuntimeError("Failed to tick epoch") from exc
         finally:
-            if 'allure' in sys.modules:
-                allure.attach((
-                    f'COMMAND: {cmd}\n'
-                    f'OUTPUT:\n {out}\n'
-                    f'ERROR: {err}\n'
-                ), 'Tick Epoch', allure.attachment_type.TEXT)
+            allure.attach((
+                f'COMMAND: {cmd}\n'
+                f'OUTPUT:\n {out}\n'
+                f'ERROR: {err}\n'
+            ), 'Tick Epoch', allure.attachment_type.TEXT)
         return
 
     # Otherwise we tick epoch using transaction