### Apache Airflow version

2.6.1

### What happened

Trying to connect to Vault using `auth_type` = `aws_iam`. I am receiving the following error: `AttributeError: 'Client' has no attribute 'auth_aws_iam'`. Looking through [the code](https://github.com/apache/airflow/blob/main/airflow/providers/hashicorp/_internal_client/vault_client.py#L303), you are using `client.auth_aws_iam`, but the [HVAC docs](https://hvac.readthedocs.io/en/stable/usage/auth_methods/aws.html#caveats-for-non-default-aws-regions) use `client.auth.aws.iam_login`. You should also add support for `boto3.Session()` to use role based access.

### What you think should happen instead

Airflow should authenticate to Vault using AWS auth.

### How to reproduce

Setup a secrets backend of `airflow.providers.hashicorp.secrets.vault.VaultBackend` and set `auth_type` = `aws_iam`. It will error out saying that the client doesn't have an attribute named `auth_aws_iam`.

### Operating System

Docker

### Versions of Apache Airflow Providers

_No response_

### Deployment

Official Apache Airflow Helm Chart

### Deployment details

_No response_

### Anything else

_No response_

### Are you willing to submit PR?

- [ ] Yes I am willing to submit a PR!

### Code of Conduct

- [X] I agree to follow this project's [Code of Conduct](https://github.com/apache/airflow/blob/main/CODE_OF_CONDUCT.md)

#
#
from __future__ import annotations
from functools import cached_property
import hvac
from hvac.api.auth_methods import Kubernetes
from hvac.exceptions import InvalidPath, VaultError
from requests import Response
from airflow.utils.log.logging_mixin import LoggingMixin
DEFAULT_KUBERNETES_JWT_PATH = "/var/run/secrets/kubernetes.io/serviceaccount/token"
DEFAULT_KV_ENGINE_VERSION = 2
VALID_KV_VERSIONS: list[int] = [1, 2]
VALID_AUTH_TYPES: list[str] = [
    "approle",
    "aws_iam",
    "azure",
    "github",
    "gcp",
    "kubernetes",
    "ldap",
    "radius",
    "token",
    "userpass",
]
class _VaultClient(LoggingMixin):