pants: reclassify st2common/tests/integration sources as test_utils

Author: cognifloyd

st2common/tests/integration/BUILD

@@ -3,8 +3,6 @@ __defaults__(
     extend=True,
 )
 
-python_sources()
-
 python_tests(
     name="tests",
     dependencies=[
@@ -13,3 +11,7 @@ python_tests(
         "conf/st2.tests1.conf:st2_tests_conf",
     ],
 )
+
+python_test_utils(
+    sources=["*.py", "!test_*.py"],
+)