[Feature] Proper/Full IAM support including profiles, roles, temporary credentials, AWS SSO, etc

[et304383]

Feature (What you would like to be added):

I would like this tool to support non-static IAM credentials in AWS. This includes:

• Profiles
• IAM roles
• Temporary credentials including a session token
• AWS SSO profiles

Motivation (Why is this needed?):

Static credentials are bad!

No but seriously, any tool that wants to be taken seriously and used by enterprise has to support enterprise access patterns to AWS. I can't possibly recommend this tool to my team when the only auth method is an IAM user with access key and secret.

[renormalize]

https://github.com/gardener/etcd-backup-restore/pull/892 brought web identity authentication for S3.

[gardener-ci-robot]

The Gardener project currently lacks enough active contributors to adequately respond to all issues. This bot triages issues according to the following rules:

• After 90d of inactivity, lifecycle/stale is applied
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You can:

• Reopen this issue with /reopen
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/close

[gardener-ci-robot]

The Gardener project currently lacks enough active contributors to adequately respond to all issues. This bot triages issues according to the following rules:

• After 90d of inactivity, lifecycle/stale is applied
• After 60d of inactivity since lifecycle/stale was applied, lifecycle/rotten is applied
• After 60d of inactivity since lifecycle/rotten was applied, the issue is closed

You can:

• Mark this issue as active with /lifecycle active
• Mark this issue as frozen with /lifecycle frozen
• Mark this issue as fresh with /remove-lifecycle stale
• Mark this issue as rotten with /lifecycle rotten
• Close this issue with /close

/lifecycle stale