Update data.forgejo.org/oci/alpine Docker tag to v3.23 (#1518)

This PR contains the following updates:

| Package | Type | Update | Change |
|---|---|---|---|
| [data.forgejo.org/oci/alpine](https://hub.docker.com/_/alpine) ([source](https://github.com/alpinelinux/docker-alpine)) | container | minor | `3.21` → `3.23` |

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Reviewed-on: https://code.forgejo.org/forgejo/end-to-end/pulls/1518
Reviewed-by: Mathieu Fenniak <mfenniak@noreply.code.forgejo.org>
Co-authored-by: Renovate Bot <bot@kriese.eu>
Co-committed-by: Renovate Bot <bot@kriese.eu>

actions/example-container/.forgejo/workflows/test.yml

@@ -3,6 +3,6 @@ jobs:
   test:
     runs-on: docker
     container:
-      image: data.forgejo.org/oci/alpine:3.21
+      image: data.forgejo.org/oci/alpine:3.23
     steps:
       - run: grep Alpine /etc/os-release