Updated documentation - How to disable IDFA collection (ios)

[Siddharth1605]

Description

Updated the documentation to include the 'without idfa' dependency (ios)

Related Issues

Issue Number: #12081
Issue : Document how to disable IDFA collection (iOS)

Checklist

• I read the [Contributor Guide] and followed the process outlined there for submitting PRs.
• My PR includes unit or integration tests for all changed/updated/fixed behaviors (See [Contributor Guide]).
• All existing and new tests are passing.
• I updated/added relevant documentation (doc comments with ///).
• The analyzer (melos run analyze) does not report any problems on my PR.
• I read and followed the [Flutter Style Guide].
• I signed the [CLA].
• I am willing to follow-up on review comments in a timely manner.

[google-cla]

Thanks for your pull request! It looks like this may be your first contribution to a Google open source project. Before we can look at your pull request, you'll need to sign a Contributor License Agreement (CLA).

View this failed invocation of the CLA check for more information.

For the most up to date status, view the checks section at the bottom of the pull request.