### Description

This is my configuration:
```yaml
images:
  airflow:
    repository: <REPO>
    tag: <TAG>
```

I'd like to be able to do the following:
```yaml
images:
  airflow:
    repository: <REPO>
    digest: <SHA_DIGEST>
```

Additionally, I've tried supplying only the repository, or placing the digest as the tag, but both don't work because of [this](https://github.com/apache/airflow/blob/c44c7e1b481b7c1a0d475265835a23b0f507506c/chart/templates/_helpers.yaml#L252). The formatting is done by `repo:tag` while I need `repo@digest`.


### Use case/motivation

I'm using Terraform to deploy Airflow.
I'm using the data source of [`aws_ecr_image`](https://registry.terraform.io/providers/hashicorp/aws/latest/docs/data-sources/ecr_image) in order to pick the `latest` image.
I want to supply to the [`helm_release`](https://registry.terraform.io/providers/hashicorp/helm/latest/docs/resources/release) of Airflow the image's digest rather than `latest` as according to the docs, it's bad practice.


### Related issues

_No response_

### Are you willing to submit a PR?

- [X] 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)

docs[index],
                )
                for c in r
            ]
            for container in jmespath.search("spec.template.spec.containers", docs[index]):
                assert "webserver-config" in [c["name"] for c in jmespath.search("volumeMounts", container)]
            assert "webserver-config" in [
                c["name"] for c in jmespath.search("spec.template.spec.volumes", docs[index])
            ]
            assert configmap_name == jmespath.search(
                "spec.template.spec.volumes[?name=='webserver-config'].configMap.name | [0]", docs[index]
            )
    def test_annotations(self):
        """
        Test Annotations are correctly applied on all pods created Scheduler, Webserver & Worker
        deployments.
        """
        release_name = "test-basic"
        k8s_objects = render_chart(
            name=release_name,
            values={
                "airflowPodAnnotations": {"test-annotation/safe-to-evict": "true"},
                "cleanup": {"enabled": True},
                "flower": {"enabled": True},
                "dagProcessor": {"enabled": True},
            },
            show_only=[
                "templates/scheduler/scheduler-deployment.yaml",
                "templates/workers/worker-deployment.yaml",
                "templates/webserver/webserver-deployment.yaml",