fix: Removing a recipe ingredient doesn't remove its links to steps

[RoSh-23]

What this PR does / why we need it:

1. Goal: To fix the issue [BUG] - Removing a recipe ingredient doesn't remove its links to steps #3956.
2. Changes made:
   • recipe_service.py: added a method which checks for non-existent references and removes them, called it inside "update_one"
   • test_recipe_crud.py: added a test method, which mimicks the issue and verfies the expected result.
3. Decisions made:
   • Fixed the recipe_service.py to prevent bad data from getting inserted, as suggested earlier by @michael-genson, by checking the non-existent references and removing them, before updating.
   • Did a small trade-off, saw the approach used by an earlier fix attempt, which made database call, I avoided any database calls since they were not required here.

Which issue(s) this PR fixes:

#3956

Special notes for your reviewer:

• Hi @hay-kot, @michael-genson, This is my first open source contribution, I would like to thank you and all the contributors for making this project open-source and providing developers around the world opportunity to learn and contribute.
• Really grateful for the team for setting up developer containers which made the process very smooth.
• Have added explanatory comments to the code.

Testing

• Wrote a test method in test_recipe_crud.py namely "test_update_with_non_existent_ingredient_references" to mimick the issue, ran it and it passed.
• Ran various scenarios from the UI and verified them through the JSON.

[RoSh-23]

Hi @michael-genson, @hay-kot
Kindly provide the approval for the workflows to run.

[RoSh-23]

Hi @hay-kot @michael-genson It is still showing 2 workflows that require approval.

[Kuchenpirat]

Workflows need manual approving by a maintainer for first time contributors which usually happens when we start reviewing the PR.
Did approve your pr workflow so we can see if everything goes through.

[RoSh-23]

Hello @Kuchenpirat, @hay-kot, @michael-genson
All checks have passed, Is it possible to review this PR now?, really looking forward to any responses, feedback etc. Thanks

[michael-genson]

We have a pretty large backlog of PRs to get through, we will get to yours once we have time. Appreciate your patience!

[RoSh-23]

We have a pretty large backlog of PRs to get through, we will get to yours once we have time. Appreciate your patience!

Really understand that, Thanks for this reply.

[RoSh-23]

Hi @michael-genson, @hay-kot, @Kuchenpirat Can this PR be reviewed now?, really looking forward to any feedback...