[Snyk] Security upgrade python from 3.12.0rc2-alpine to 3.13.0a3-alpine

[jamesgeddes]

This PR was automatically created by Snyk using the credentials of a real user.

Keeping your Docker base image up-to-date means you’ll benefit from security fixes in the latest version of your chosen image. #### Changes included in this PR - docker/backend/Dockerfile We recommend upgrading to `python:3.13.0a3-alpine`, as this image has only 0 known vulnerabilities. To do this, merge this pull request, then verify your application still works as expected. Some of the most important vulnerabilities in your base image include: | Severity | Priority Score / 1000 | Issue | Exploit Maturity | | :------: | :-------------------- | :---- | :--------------- | |  | **614** | CVE-2023-5363
[SNYK-ALPINE318-OPENSSL-6032386](https://snyk.io/vuln/SNYK-ALPINE318-OPENSSL-6032386) | No Known Exploit | |  | **614** | CVE-2023-5363
[SNYK-ALPINE318-OPENSSL-6032386](https://snyk.io/vuln/SNYK-ALPINE318-OPENSSL-6032386) | No Known Exploit | |  | **514** | Improper Check for Unusual or Exceptional Conditions
[SNYK-ALPINE318-OPENSSL-6055795](https://snyk.io/vuln/SNYK-ALPINE318-OPENSSL-6055795) | No Known Exploit | |  | **514** | Improper Check for Unusual or Exceptional Conditions
[SNYK-ALPINE318-OPENSSL-6055795](https://snyk.io/vuln/SNYK-ALPINE318-OPENSSL-6055795) | No Known Exploit | |  | **436** | CVE-2023-6129
[SNYK-ALPINE318-OPENSSL-6152404](https://snyk.io/vuln/SNYK-ALPINE318-OPENSSL-6152404) | No Known Exploit | --- **Note:** _You are seeing this because you or someone else with access to this repository has authorized Snyk to open fix PRs._ For more information: 🧐 [View latest project report](https://app.snyk.io/org/jamesgeddes/project/59012dc0-c784-47ae-8b68-6542f3f189eb?utm_source=github&utm_medium=referral&page=fix-pr) 🛠 [Adjust project settings](https://app.snyk.io/org/jamesgeddes/project/59012dc0-c784-47ae-8b68-6542f3f189eb?utm_source=github&utm_medium=referral&page=fix-pr/settings) [//]: # 'snyk:metadata:{"prId":"e735417c-422d-4000-945f-248edd307a87","prPublicId":"e735417c-422d-4000-945f-248edd307a87","dependencies":[{"name":"python","from":"3.12.0rc2-alpine","to":"3.13.0a3-alpine"}],"packageManager":"dockerfile","projectPublicId":"59012dc0-c784-47ae-8b68-6542f3f189eb","projectUrl":"https://app.snyk.io/org/jamesgeddes/project/59012dc0-c784-47ae-8b68-6542f3f189eb?utm_source=github&utm_medium=referral&page=fix-pr","type":"auto","patch":[],"vulns":["SNYK-ALPINE318-OPENSSL-6032386","SNYK-ALPINE318-OPENSSL-6055795","SNYK-ALPINE318-OPENSSL-6152404"],"upgrade":["SNYK-ALPINE318-OPENSSL-6032386","SNYK-ALPINE318-OPENSSL-6032386","SNYK-ALPINE318-OPENSSL-6055795","SNYK-ALPINE318-OPENSSL-6055795","SNYK-ALPINE318-OPENSSL-6152404"],"isBreakingChange":false,"env":"prod","prType":"fix","templateVariants":["updated-fix-title","priorityScore"],"priorityScoreList":[614,514,436],"remediationStrategy":"vuln"}' --- **Learn how to fix vulnerabilities with free interactive lessons:** 🦉 [Learn about vulnerability in an interactive lesson of Snyk Learn.](https://learn.snyk.io/?loc=fix-pr)

[sonarcloud[bot]]

Quality Gate passed

Kudos, no new issues were introduced!

0 New issues
0 Security Hotspots
No data about Coverage
0.0% Duplication on New Code

See analysis details on SonarCloud

[giulio-giunta]

This is a duplicate of #711