Add e2e to CI and skip run on forks

[lucacome]

This pull request includes several updates to the GitHub Actions workflows and configuration files. The main changes involve removing the build action and preventing the e2e workflow from running on forks.

The build action was only used once so I thought it would make more sense to just use the steps directly.

Removal of build action:

• .github/actions/build/action.yaml: Removed the entire build action which included steps for setting up Go, generating templ code, building the binary, and uploading the binary artifact.

Updates to setup action:

• .github/actions/setup/action.yaml: Updated the AWS credentials action to version v4.1.0 and replaced the download-artifact action with the cache action for fetching cached artifacts. [1] [2]

Refactoring of e2e workflow:

• .github/workflows/e2e.yaml:
  • Modified the push and pull_request triggers to use a multi-line format for branches.
  • Updated the runs-on field to use ubuntu-24.04 and added a condition to check if the repository is not a fork.
  • Replaced the build action with individual steps for setting up Go, generating templ code, running GoReleaser, and caching artifacts.
  • Updated the checkout action to version v4.2.2 and removed the binary_name environment variable. [1] [2] [3] [4]

Closes #194

[lucacome]

@cterence what do you think about this?

[cterence]

Thank you very much for your work! I disabled the e2e tests on my repo because there is a non-identified issue in tailout which made the VMs never shutdown which got me a non-zero AWS bill. I will not enable them unless we find a way to prevent this from happening. If you're willing to work on this aspect and find a way to prevent this, I'll be happy to reconsider!