fix: role assumption through profiles not working properly in certain situations

[ShadowCat567]

Description of changes

This PR fixes 2 bugs that affect people who get their credentials from profiles that look like this:

[profile test-profile]
role_arn=arn:aws:iam::<account number>:role/test-role
source_profile=other-profile

1. @aws-sdk/credential-providers
@aws-sdk/credential-providers uses v4 of @smithy/property-providers. This is a problem because our bundling solution (pkg) does not support dynamic imports, which were introduced in v4 of @smithy/property-providers. So I downgraded us to the newest version that still uses v3 of @smithy/property-providers until we come up with a more permanent solution.
   Not sure why this change specifically broke profiles that use a role and another profile to get credentials since profiles that got credentials through other methods worked fine for me.

2. identity.expiration.getTime is not a function
   The expiration field within credentials of profiles that get credentials through a role and another profile is a string instead of a Date. This was fine in AWS SDK V2, since it was more flexible with types, however AWS SDK V3 is much stricter with typing so the expiration field needs to get converted to a Date before it gets used in any clients.

Issue #, if available

#14290

Description of how you validated changes

Discovered the first issue after 14.2.1 was released and was able to reproduce the second issue and verify that both are fixed by these changes.

Checklist

• PR description included
• yarn test passes
• Tests are changed or added
• Relevant documentation is changed or added (and PR referenced)
• New AWS SDK calls or CloudFormation actions have been added to relevant test and service IAM policies
• Pull request labels are added

By submitting this pull request, I confirm that my contribution is made under the terms of the Apache 2.0 license.