chore(deps): update python docker tag to v3.12 (#485)

[![Mend
Renovate](https://app.renovatebot.com/images/banner.svg)](https://renovatebot.com)

This PR contains the following updates:

| Package | Type | Update | Change |
|---|---|---|---|
| python | stage | minor | `3.10-alpine` -> `3.12-alpine` |

---

### Configuration

📅 **Schedule**: Branch creation - At any time (no schedule defined),
Automerge - At any time (no schedule defined).

🚦 **Automerge**: Enabled.

♻ **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 has been generated by [Mend
Renovate](https://www.mend.io/free-developer-tools/renovate/). View
repository job log
[here](https://developer.mend.io/github/allenporter/flux-local).

<!--renovate-debug:eyJjcmVhdGVkSW5WZXIiOiIzNy4xMDMuMSIsInVwZGF0ZWRJblZlciI6IjM3LjEwMy4xIiwidGFyZ2V0QnJhbmNoIjoibWFpbiJ9-->

Co-authored-by: renovate[bot] <29139614+renovate[bot]@users.noreply.github.com>

Dockerfile

@@ -1,4 +1,4 @@
-FROM python:3.10-alpine as base
+FROM python:3.12-alpine as base
 
 RUN apk add --no-cache ca-certificates git