### Description

Support mounting to multiple namespaces with the Hashicorp Vault Secrets Back-end

### Use case/motivation

As a data engineer I wish to utilize secrets stored in multiple mount paths (to support connecting to multiple namespaces)  without having to mount to a higher up namespace.

### Related issues

_No response_

### Are you willing to submit a 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 airflow.providers.google.cloud.utils.credentials_provider import (
            _get_scopes,
            get_credentials_and_project_id,
        )
        scopes = _get_scopes(self.gcp_scopes)
        credentials, _ = get_credentials_and_project_id(
            key_path=self.gcp_key_path, keyfile_dict=self.gcp_keyfile_dict, scopes=scopes
        )
        if self.auth_mount_point:
            _client.auth.gcp.configure(credentials=credentials, mount_point=self.auth_mount_point)
        else:
            _client.auth.gcp.configure(credentials=credentials)
    def _auth_azure(self, _client: hvac.Client) -> None:
        if self.auth_mount_point:
            _client.auth.azure.configure(
                tenant_id=self.azure_tenant_id,
                resource=self.azure_resource,
                client_id=self.key_id,
                client_secret=self.secret_id,
                mount_point=self.auth_mount_point,
            )
        else:
            _client.auth.azure.configure(
                tenant_id=self.azure_tenant_id,
                resource=self.azure_resource,
                client_id=self.key_id,
                client_secret=self.secret_id,
            )
    def _auth_aws_iam(self, _client: hvac.Client) -> None: