Add dynamic task mapping example

[Jorricks]

Closes #26677

[pierrejeambrun]

We have an embedded example in the doc in dynamic-task-mapping.rst (which is the same appart from the dag_id), can we point to this new example to avoid duplication ?

Also, we are PR driven, meaning that you don't need to create an issue before opening a PR :)

[Jorricks]

We have an embedded example in the doc in dynamic-task-mapping.rst (which is the same appart from the dag_id), can we point to this example to avoid duplication ?

Also, we are PR driven, meaning that you don't need to create an issue before opening a PR :)

Yes sorry, originally just wanted to raise an issue but didn't want to come over lazy, so also created an example PR.

Anyways, I indeed copied it from there. I think it's good to have an example dag in the code base to test UI functionality for example

[josh-fell]

@Jorricks You might be running up against the same test issues as in #24085 when this was attempted before. However, I do think a core example would indeed be useful if we can overcome the test failures.

[potiuk]

@Jorricks You might be running up against the same test issues as in #24085 when this was attempted before. However, I do think a core example would indeed be useful if we can overcome the test failures.

Indeed. It would have been very useful :).

[Jorricks]

Closed this as the other MRs have more priority and I don't have the time to work on making this work unfortunately :'(