update(ci): porting CI from test-infra to GHA.

[cappellinsamuele]

What type of PR is this?

/kind design

Any specific area of the project related to this PR?

/area tests

What this PR does / why we need it:

This PR is needed to run the CI directly in this repository instead of running it from test-infra.

Which issue(s) this PR fixes:

Special notes for your reviewer:

Does this PR introduce a user-facing change?:

NONE

[poiana]

Welcome @cappellinsamuele! It looks like this is your first PR to falcosecurity/plugin-sdk-go 🎉

[poiana]

Hi @cappellinsamuele. Thanks for your PR.

I'm waiting for a falcosecurity member to verify that this patch is reasonable to test. If it is, they should reply with /ok-to-test on its own line. Until that is done, I will not automatically test new commits in this PR, but the usual testing commands by org members will still work. Regular contributors should join the org to skip this step.

Once the patch is verified, the new status will be reflected by the ok-to-test label.

I understand the commands that are listed here.

Instructions for interacting with me using PR comments are available [here](https://git.k8s.io/community/contributors/guide/pull-requests.md). If you have questions or suggestions related to my behavior, please file an issue against the [kubernetes/test-infra](https://github.com/kubernetes/test-infra/issues/new?title=Prow%20issue:) repository.

[FedeDP]

/hold

[FedeDP]

I'd also remove the build.sh script that is useless after this one :)

[FedeDP]

I actually think we should keep build.sh script until we cleanup the prow job ;)

[FedeDP]

/cc @jasondellaluce

[poiana]

[APPROVALNOTIFIER] This PR is APPROVED

This pull-request has been approved by: cappellinsamuele, jasondellaluce

The full list of commands accepted by this bot can be found here.

The pull request process is described here

Needs approval from an approver in each of these files: - ~~[OWNERS](https://github.com/falcosecurity/plugin-sdk-go/blob/main/OWNERS)~~ [jasondellaluce] Approvers can indicate their approval by writing `/approve` in a comment Approvers can cancel approval by writing `/approve cancel` in a comment

[poiana]

LGTM label has been added.

Git tree hash: e23a27e62440cd749e78f10bb2d2e10f3d5e34eb

[jasondellaluce]

/unhold