Dependabot reports for potential security vulnerabilities

[532910]

https://github.com/nspcc-dev/neo-go/security/dependabot

[roman-khimov]

I know about it, but I'm not sure we have an actual problem here, because originally it's for a different version of the package we use. But it needs to be checked.

[532910]

I believe the main actual problem is in the banner itself, as github is the front page for our code.

[roman-khimov]

It's not visible to outsiders.

[roman-khimov]

I've just looked at the code, and it seems like it affects us. As well as go-yaml/yaml#665, so we need to move on with #2085.

[roman-khimov]

Fixed by #2527.