[6.17.z] Update dependancy-merge workflow as for other z-stream branches

[Gauravtalreja1]

Problem Statement

dependancy-merge GHA using same configuration as the master causing failure in the automerge.

Solution

Update dependancy-merge workflow as for other z-stream branches

Related Issues

Skipped workflow - https://github.com/SatelliteQE/robottelo/actions/runs/13440837741/job/37554615946?pr=17650
Previously handled for 6.16.z in - #16504

[JacobCallahan]

@Gauravtalreja1 can you elaborate on what the problem being solved here is?

[Gauravtalreja1]

@JacobCallahan Sure, We've different dependancy automerge GHA for master and zstream branches, so for example if you see GHA of master branch you'd find dependancy PRs opened from dependabot user which we check with if: github.event.pull_request.user.login == 'dependabot[bot]', but in case of Zstream branches, it would be cherrypicked by our automation/bot user, so in case zstream branches we just check if dependencies label is added to the cherrypicked PRs.
For example, workflow linked in the description is skipped because the PR is not opened by dependabot user

[jyejare]

@Gauravtalreja1 @ogajduse We also need to update the automatic branching logic to do this change everytime. No need to do in this PR though.