chore(deps): update rust docker digest to af306cf (#52)

This PR contains the following updates:

| Package | Type | Update | Change |
|---|---|---|---|
| rust | final | digest | `d8fb475` -> `af306cf` |

---

### Configuration

📅 **Schedule**: Branch creation - Between 08:00 AM and 10:59 AM ( * 8-10
* * * ) in timezone Europe/Paris, Automerge - At any time (no schedule
defined).

🚦 **Automerge**: Disabled by config. Please merge this manually once you
are satisfied.

♻ **Rebasing**: Whenever PR becomes conflicted, or you tick the
rebase/retry checkbox.

🔕 **Ignore**: Close this PR and you won't be reminded about this update
again.

---

- [ ] <!-- rebase-check -->If you want to rebase/retry this PR, check
this box

---

This PR was created by Renovate.

<details>
<summary>Details</summary>

Check the [default
configuration](https://redirect.github.com/doctolib/renovate-config) and
[documentation](https://doctolib.atlassian.net/wiki/spaces/EE/pages/1882882081/Renovate+Dependencies+Management).

See the [logs on
Datadog](https://app.datadoghq.com/logs?query=source%3Agithub%20%40git.repository_url%3A%22https%3A%2F%2Fgithub.com%2Fdoctolib%2Frenovate-config.git%22%20%40ci.pipeline.name%3A%28Run%5C%20Renovate%5C%20%5C%28%2A%20OR%20%22Run%20Renovate%20on%20doctolib%2Fdoctolib%22%29%20%40name%3Arenovate%20%40repository%3A%2A%2A%2A%2Fcouchbase-lite-rust&agg_m=count&agg_m_source=base&agg_t=count&cols=%40repository&fromUser=false&messageDisplay=inline&refresh_mode=sliding&storage=hot&stream_sort=time%2Cdesc&viz=stream).
To replay this update, you can use the following `packageRules` on the
[Manual
Run](https://redirect.github.com/doctolib/renovate-config/actions/workflows/manual_run.yml)
page: `[{"matchPackageNames": ["*"], "enabled": false},
{"matchPackageNames": ["rust"], "enabled": true}]`

</details>

<!--renovate-debug:eyJjcmVhdGVkSW5WZXIiOiI0MS40My4yIiwidXBkYXRlZEluVmVyIjoiNDEuNDMuMiIsInRhcmdldEJyYW5jaCI6Im1haW4iLCJsYWJlbHMiOlsiYXV0by1hcHByb3ZlIiwiZGVwZW5kZW5jaWVzIiwiZGlnZXN0IiwiZG9ja2VyZmlsZSJdfQ==-->

Co-authored-by: doctolib-renovate[bot] <161009298+doctolib-renovate[bot]@users.noreply.github.com>

Author: doctolib-renovate[bot]

Dockerfile

@@ -1,4 +1,4 @@
-FROM --platform=amd64 rust@sha256:d8fb475b1e114a71c7c841b9e5024de21af70c732acb019edff64207eec4a6a8 AS strip-stage
+FROM --platform=amd64 rust@sha256:af306cfa71d987911a781c37b59d7d67d934f49684058f96cf72079c3626bfe0 AS strip-stage
 ARG DIRNAME
 RUN apt-get update
 RUN apt-get -y install binutils binutils-aarch64-linux-gnu