[NO-ISSUE] Remove MongoDB leftovers duo to ASF restrictions

[ricardozanini]

Many thanks for submitting your Pull Request :heart:!

@porcelli the Jobs Service MongoDB image was removed in the previous PR. In this one, I just removed the leftovers from ephemeral.

@wmedvede since you're the JS maintainer, can you please take a look? Please note that we might remove the all-in-one image now since it only supports one persistence model.

We can't ship MongoDB-related artifacts duo to ASF policy restrictions.

Please make sure your PR meets the following requirements:

• [ ] You have read the contributors guide
• [ ] Pull Request title is properly formatted: [KOGITO|RHPAM-XYZ] Subject
• [ ] Pull Request contains link to the JIRA issue
• [ ] Pull Request contains description of the issue
• [ ] Pull Request does not include fixes for issues other than the main ticket
• [ ] Your feature/bug fix has a testcase that verifies it
• [ ] You've tested the new feature/bug fix in an actual OpenShift cluster
• [ ] You've added a RELEASE_NOTES.md entry regarding this change

How to retest this PR or trigger a specific build:

- (Re)run Jenkins tests Please add comment: Jenkins [test|retest] this

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[ricardozanini]

Flacky tests, unrelated.