Log cron_jobs configuration instead of raising exception

What does this MR do?

Log cron_jobs configuration errors and remove invalid key <-> values from the configuration hash instead of raising an exception. This has been discussed at #20010 (closed).

Fixes #20010 (closed)

Are there points in the code the reviewer needs to double check?

Why was this MR needed?

Original implementation !5318 (merged), introduced a regression with our docker packaging: #20010 (closed).

What are the relevant issue numbers?

• #20010 (closed)
• #18378 (closed)

Does this MR meet the acceptance criteria?

• CHANGELOG entry added
• Documentation created/updated
• API support added
• Tests
  • Added for this feature/bug
  • All builds are passing
• Conform by the style guides
• Branch has no merge conflicts with master (if you do - rebase it please)
• Squashed related commits together