[BUG] salt-cloud using ec2 fails to authenticate properly when a AWS SESSION TOKEN is required. FIX INCLUDED

Description
My organization has configured AWS to require an ID, a KEY and a session token when authenticating to the API.

So we set (in a shell environement)

$ export AWS_ACCESS_KEY_ID="******"
$ export AWS_SECRET_ACCESS_KEY="******"
$ export AWS_SESSION_TOKEN="******"

and everything works.
Note that this is from a laptop/workstation outside of AWS itself - I am NOT on an instance.

salt-cloud using the ec2 driver should be able to auth with all 3 when required.

No, I cannot redo our aws config to change this - its done by a cloud team.

Setup
From my /etc/salt/cloud.providers.d/ec2.conf :

 # Set the EC2 access credentials (see below)
  id: "******"
  key: "******"
 
  # If 'role_arn' is specified the above credentials are used to
  # to assume to the role. By default, role_arn is set to None.
  #role_arn: arn:aws:iam::207348486369:role/NIH-AWS-SystemAdministrator-SSA

Steps to Reproduce the behavior

1. set only id and key in the relevant config
2. attempt to use the AWS api - I picked --list-locations for simplicity

salt-cloud --list-locations ec2
[ERROR ] AWS Response Status Code and Error: [401 401 Client Error: Unauthorized for url: https://ec2.us-east-1.amazonaws.com/?Action=DescribeRegions&Version=2016-11-15] {'Errors': {'Error': {'Code': 'AuthFailure', 'Message': 'AWS was not able to validate the provided access credentials'}}, 'RequestID': '8ed6a97c-ff13-4a1d-9ef7-c6af19a1f8ba'}
[ERROR ] Failed to get the output of 'ec2.avail_locations()': string indices must be integers
aws-ssa:
----------

Expected behavior
If needed, a 3rd authentication variable for the "token" should be accepted and used.

MINIMUM FIX
https://github.com/saltstack/salt/blob/b0bf7eba9b6c98153fb328ac823be421c92f524d/salt/utils/aws.py#L175C22-L175C22

line #175 should be changed to

        ret_credentials = provider["id"], provider["key"], provider["token"]

and then the user can set the "token" variable in the config.
For users not needing a token, an empty string should work (I can't test this obviously).

MORE COMPLETE FIX
For line #175, code like this should cover both kinds of users:

       if provider.get("token") is not None:
            ret_credentials = provider["id"], provider["key"], provider["token"]
        else:
            ret_credentials = provider["id"], provider["key"], ""

I believe similar code should be used for lines
https://github.com/saltstack/salt/blob/b0bf7eba9b6c98153fb328ac823be421c92f524d/salt/utils/aws.py#L160
https://github.com/saltstack/salt/blob/b0bf7eba9b6c98153fb328ac823be421c92f524d/salt/utils/aws.py#L165

Versions Report

> salt --versions-report

Salt Version:
          Salt: 3005

Dependency Versions:
          cffi: 1.14.6
      cherrypy: unknown
      dateutil: 2.8.0
     docker-py: Not Installed
         gitdb: 4.0.5
     gitpython: 3.1.12
        Jinja2: 3.1.0
       libgit2: 1.6.4
      M2Crypto: Not Installed
          Mako: 1.1.4
       msgpack: 1.0.2
  msgpack-pure: Not Installed
  mysql-python: Not Installed
     pycparser: 2.21
      pycrypto: 3.15.0
  pycryptodome: 3.9.8
        pygit2: 1.12.0
        Python: 3.10.12 (main, Jun 15 2023, 07:47:12) [Clang 14.0.0 (clang-1400.0.29.202)]
  python-gnupg: 0.4.8
        PyYAML: 5.4.1
         PyZMQ: 23.2.0
         smmap: 3.0.2
       timelib: 0.2.4
       Tornado: 4.5.3
           ZMQ: 4.3.4

System Versions:
          dist: darwin 21.6.0
        locale: utf-8
       machine: arm64
       release: 21.6.0
        system: Darwin
       version: 12.6.5 arm64

This was installed on monterey via brew.

Start in salt/utils/aws.py at the referenced lines 160, 165, and 175, then trace how provider credentials reach the EC2 API. Reproduce the issue with salt-cloud --list-locations ec2 using a required AWS session token. Done means EC2 authentication works with id, key, and token while existing users without a token remain supported.