scripts/lint.sh: There are warnings which are ignored

[0xFelix]

What happened:

scripts/lint.sh runs yamllint with -d relaxed which leads to some errors becoming warnings instead. yamllint does exit with code 0 if only warnings were found, which leads to warnings being silently ignored when linting in presubmit lanes.

What you expected to happen:

yamllint should be as strict as possible, so we don't ignore warnings silently.

How to reproduce it (as minimally and precisely as possible):

Look at log output of pull-common-instancetypes lane.

Additional context:
Add any other context about the problem here.

Environment:

• KubeVirt version (use virtctl version): N/A
• Kubernetes version (use kubectl version): N/A
• VM or VMI specifications: N/A
• Cloud provider or hardware configuration: N/A
• OS (e.g. from /etc/os-release): N/A
• Kernel (e.g. uname -a): N/A
• Install tools: N/A
• Others: N/A