test: less fragile integration suite [ci skip]

See coop-cloud/organising#584
See coop-cloud/organising#595

tests/integration/app_run.bats

@@ -18,10 +18,7 @@ setup(){
 }
 
 teardown(){
-  # https://github.com/bats-core/bats-core/issues/383#issuecomment-738628888
-  if [[ -z "${BATS_TEST_COMPLETED}" ]]; then
-    _undeploy_app
-  fi
+  _undeploy_app
 }
 
 @test "validate app argument" {
@@ -51,8 +48,6 @@ teardown(){
   run $ABRA app run "$TEST_APP_DOMAIN" DOESNTEXIST ls
   assert_failure
   assert_output --partial 'no containers matching'
-
-  _undeploy_app
 }
 
 # bats test_tags=slow
@@ -62,6 +57,4 @@ teardown(){
   run $ABRA app run "$TEST_APP_DOMAIN" app ls /
   assert_success
   assert_output --partial 'root'
-
-  _undeploy_app
 }