Remove parallelity of integration tests

Description

Related Issue

Motivation and Context

How Has This Been Tested?

Screenshots (if appropriate):

Types of changes

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to change)

Checklist:

• My code follows the code style of this project.
• My change requires a change to the documentation.
• I have updated the documentation accordingly.
• I have read the CONTRIBUTING document.
• I have added tests to cover my changes.
• All new and existing tests passed.

.gitlab/ci/.test.yml

@@ -37,5 +37,5 @@ integration-test-gosdn:
         - mv artifacts/ssl/gosdn/private artifacts/ssl/
         - make build-gosdn
         - cd artifacts && GOSDN_ADMIN_PASSWORD=TestPassword ./gosdn --config ../controller/configs/integration-test-gosdn.toml --security secure &
-        - INTEGRATION_TEST_CONTROLLER_URL="localhost:55055" go test ./integration-tests/*
+        - INTEGRATION_TEST_CONTROLLER_URL="localhost:55055" go test -p 1 ./integration-tests/*
     <<: *test