Assume Role With SAML and Update Credentials File

### Describe the feature

I would like to propose a function similar to `aws sts assume-role-with-saml` but instead of returning the credentials to stdout, it will update the credentials file. There is already precedence for the aws cli updating files via the `aws codeartifact login` command. I think this would be a nice quality of life feature to save clients copying and pasting the credentials or writing their own code to update the credentials file.

### Use Case

When I log in with SAML, I have to copy and paste the returned credentials into the credentials file, or I have to write code to update the credentials file. It would be nice to have a native function to update the credentials file for me.

### Proposed Solution

_No response_

### Other Information

_No response_

### Acknowledgements

- [ ] I may be able to implement this feature request
- [ ] This feature might incur a breaking change

### CLI version used

aws-cli/2.13.25 Python/3.11.5 Windows/10 exe/AMD64 prompt/off

### Environment details (OS name and version, etc.)

Windows 10