Fix dependabot labeler and workflows

[ChristianZaccaria]

Issue link

Jira: https://issues.redhat.com/browse/RHOAIENG-11457

What changes have been made

• Further limited number of PRs generated.

• Changes in this repo's settings:

  We are dropping the merge queue feature as it seems it's not properly maintained with major issues found unresolved for over a year.

  One benefit seen from merge queue is that it ensures PRs are tested against the target branch. Since we won't be using this feature, I've enabled "Require branches to be up to date before merging" GitHub feature in the main branch. By enabling this, all PRs will require to rebase before they can be merged to main and this way ensure code stability and integration.

• Due to said change, I removed the need to run tests (e2e, unit-tests) again when commits are merged to main as they would have been already tested in the PR with the changes from the target branch.

• Use newly created token to allow the codeflare-machine-account to add labels to specifically PRs created by Dependabot.

Verification steps

• Fixed the dependabot labeler: The "codeflare-machine-account" added the lgtm and approved labels to the following PR successfully by using the new GH CLI token with minimal permissions. In this PR, an adjustment is made so that the dependabot-labeler will only work for Dependabot PRs i.e., where github.actor == 'dependabot[bot]'

  Test PR using new GH CLI Token to allow the codeflare-machine-account to add labels to dependabot PRs: Test PR #739 (automatically merged after status checks passed).

Checks

• I've made sure the tests are passing.
• Testing Strategy
  • Unit tests
  • Manual tests
  • Testing is not required for this change

[ChristianZaccaria]

In this PR, you'll notice that the e2e, unit-tests, precommit, and tide checks are marked as Required for merging. I've configured our branch settings to enforce this rule without any bypass options, ensuring enhanced security.

[Bobbins228]

@ChristianZaccaria Can you provide the 2 PRs in the verification steps? I think you might be missing links :)

[ChristianZaccaria]

@Bobbins228 ohh sorry, it's meant to be a single bullet point / one PR. - I could have worded it better :)

The PR is proof of the the machine adding the required labels, waiting for status checks to pass, and eventually automatically merging the PR.

[KPostOffice]

Looks good, just one question.

[openshift-ci]

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