Resolve "Investigate GitLab-CI services don't reach each other"

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.

Related to #335

.gitlab-ci.yml

@@ -7,6 +7,7 @@ variables:
     GOLANG_VERSION: "1.22"
     GNMI_TARGET_IMAGE: registry.code.fbi.h-da.de/danet/gnmi-target/debian:master
     GNMI_TARGET_INTEGRATION_IMAGE: "$CI_REGISTRY_IMAGE/gnmi-target-integration-test:${CI_COMMIT_SHA}"
+    DOCKER_TLS_CERTDIR: "/certs"
 
 workflow:
   rules: