Update GitLab Provider API Version

[makkus183]

Hey!

Issue

The GitLab API V3 is no longer supported. and returns:

{
"error": "API V3 is no longer supported. Use API V4 instead."
}

My env

PHP: 7.4

Provider: GitLab

Provider options:

Thanks 😺

[ADmad]

You don't really need to open an issue if you are going to open a PR shortly after :)

[makkus183]

Oh ok, sorry :) I thought a PR has to be related to an issue. As you already recognized i am quite new in the contrib business on github :)

[ADmad]

No worries, thanks for the PRs.