Update linter and fix issues found

[albertvaka]

Bumps the linter docker image and fixes the following warnings:

• File permissions not being explicit.
• role_name and namespace missing from metadata.
• Wildcards used in pre/post tasks are not expanded (confirmed manually in 2.6 and 2.10)-> I removed the tasks since they never worked so nobody must be using them.

[KSerrania]

LGTM.

About the file permissions: we're already making the Agent 6/7 main config file not world-readable. Should we do the same for the integrations config files, the config dir itself? And should we do the same for the Agent 5 config too?

[albertvaka]

I've just added a FIXME for A5, the same way I added a FIXME for Windows in the original changes. Those are breaking changes so they will have to wait until a new major version. The Windows one is a bit more worrying than A5. About the directories themselves, I don't think it's a security issue that they are accessible by anyone.

[kayayarai]

No docs review required