Feat: stop sending external_id for env0_aws_credentials resource

[TomerHeber]

Issue & Steps to Reproduce / Feature Request

fixes #591

Solution

1. Removed external_id from all the locations I found,
2. Updated unit tests, examples, acceptance tests, and integration tests.

[TomerHeber]

Removed also from cost credentials...
I was guessing this also needs to be removed. I hope this was correct.
(Worst case, I'll add it back).

[yaronya]

@TomerHeber is this ready for review?

[avnerenv0]

@yaronya it doesn't matter.

@TomerHeber sorry but we've had some blowback from our customers regarding this sudden change.
We'll need to make the external_id optional as a first deprecation step - with some wording in the docs that "it will be removed entirely in the near future".
Can you do that here? Or open another PR if you prefer?

Thanks

[TomerHeber]

@yaronya it doesn't matter.

@TomerHeber sorry but we've had some blowback from our customers regarding this sudden change. We'll need to make the external_id optional as a first deprecation step - with some wording in the docs that "it will be removed entirely in the near future". Can you do that here? Or open another PR if you prefer?

Thanks

@yaronya @avnerenv0 - closing this PR (can re-open in the future).
I will add a deprecated message instead.

[avnerenv0]

deprecation period is over - we want this removed

[avnerenv0]

@TomerHeber the API is going to ignore external_id from now on and we wanna remove it from the provider - can you resolve the conflicts here please?

[avnerenv0]

please resolve the conflicts - other than that - ready to merge 👍

[avnerenv0]

Assume role - deprecate External ID entirely