Add linting based on the elastic-agent-libs for Beats

[cmacknz]

Now that a base configuration for golangci-lint has been created and setup for elastic-agent-libs we should do the same for the beats repository.

See #30150 for the related PRs.

Since the beats repository is so large we will need to be more careful when rolling it out to ensure the new linters do not slow down the development workflow.

We will likely also only want to have the linter only prevent new issues initially, rather than fixing all existing issues. PRs to address existing issues can be quite large, for example #30483.

See go-libaudit for an example of how to configure the linter to only find new issues: https://github.com/elastic/go-libaudit/blob/227948a588b4c181d09a55154a476372525be193/.github/workflows/golangci-lint.yml#L29-L30

[elasticmachine]

Pinging @elastic/elastic-agent-data-plane (Team:Elastic-Agent-Data-Plane)

[rdner]

See go-libaudit for an example of how to configure the linter to only find new issues: https://github.com/elastic/go-libaudit/blob/227948a588b4c181d09a55154a476372525be193/.github/workflows/golangci-lint.yml#L29-L30

Just to avoid future problems, this configuration simply does not work. I tested it manually and had to use --new-from-rev and --whole-file additionally to this flag (see https://github.com/elastic/elastic-agent-libs/pull/11/files#diff-520109d035a196d29d0a86e9c4e6c98e98abf056141b84df68c0d48167b87b25R127-R132

• First of all, we need changes since master, not just new issues
• Second, the default behaviour of --new-from-rev is supposed to inspect only diffs and seems like it's broken in the linter at the moment since it does not report anything.

[cmacknz]

I assigned this to you @rdner, if you run out of time for it feel free to send it back to me.

[jlind23]

@rdner @cmacknz is this something we made some progress on? Should we postpone it to another release or should we keep it here?

[cmacknz]

I think it stalled due to other priorities, I don't think @rdner is actively working on this.

It's not critical to do in 8.2. We can unassign it change the label if we want and someone can take it once they have time for it.

[rdner]

@jlind23 @cmacknz I was planning to get it done this week, perhaps even tomorrow.

[cmacknz]

Perfect, assigned back to you then