feat!: Update supported versions and add support for private key creation

[bryantbiggs]

Description

• Minimum supported version of Terraform AWS provider updated to v4.21 to support latest resources
• Minimum supported version of Terraform updated to v1.0
• The variable create_key_pair is now simply create

See UPGRADE-2.0.md for full list of chagnes

Motivation and Context

• Update versions used to latest GA versions
• Add support for creating private/public keys used in key pair resource

Breaking Changes

• Yes

How Has This Been Tested?

• [x] I have updated at least one of the examples/* to demonstrate and validate my change(s)
• [x] I have tested and validated these changes using one or more of the provided examples/* projects
• [x] I have executed pre-commit run -a on my pull request

[antonbabenko]

This PR is included in version 2.0.0 :tada:

[github-actions[bot]]

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