(docs): Broken links are scattered throughout docs following repo restructure

[yo-ga]

Describe the issue

After the related remodeling task, the integration testing document isn't updated.
It makes the developers confused and hard to follow.

Links

INTEGRATION_TESTS.md

[peterwoodworth]

I've been having some issues with our documentation in general since the change, lots of broken links everywhere! i'm going to use this issue to consolidate all broken links if that's okay with you 🙂

[yo-ga]

@peterwoodworth Any will do.

[plumdog]

Main thing I've hit is the links from the main docs that link to the source code, eg:
https://docs.aws.amazon.com/cdk/api/v2/docs/aws-cdk-lib.aws_s3.Bucket.html

Which has a "(source)" link next to "TypeScript". This links to https://github.com/aws/aws-cdk/blob/v2.73.0/packages/@aws-cdk/aws-s3/lib/bucket.ts#L1623, the old location in the repo. (This location existed as of 2.72.0 but is now gone).

Edit: I should add, strictly, this is tied to the 2.73.0 release (which contained the restructure) rather than to the restructure itself, as the "source" links reference the latest release's tag on GitHub.

[yo-ga]

Actually, this original scope is more likely the same as the meaning for the label docs/repo-general.
@peterwoodworth If you are like to collect and track the whole documented issues, here the better way is.
You create the tracking issue on your own. After doing that, you link the issues, including this one.

[peterwoodworth]

Also this issue #26037

[peterwoodworth]

#26662