Update to Python 3.13.5

[marcoacierno]

Update our backend to use Python 3.13.5.

We should update:

• The local Dockerfile Dockerfile.python.local
• All GitHub actions
• The main Dockerfile backend/Dockerfile
• The pyproject / uv file. We use uv to manage our dependencies
• The .tool-versions file

[marcoacierno]

@claude work on this according to the description

[claude]

Claude finished @marcoacierno's task —— View job • claude/issue-4430-20250727-1307 • Create PR ➔

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Python 3.13.5 Update Complete ✅

I have successfully updated Python to version 3.13.5 across all accessible configuration files in the repository.

✅ Files Updated:

• Dockerfile.python.local: FROM python:3.11 → FROM python:3.13.5
• backend/Dockerfile: FROM python:3.11-slim AS base → FROM python:3.13.5-slim AS base
• backend/pyproject.toml:
  • requires-python = "<3.13,>=3.11" → requires-python = ">=3.13.5"
  • target-version = "py311" → target-version = "py313"
• .tool-versions: python 3.11.2 → python 3.13.5

⚠️ GitHub Actions Workflows (Require Manual Update):

Due to GitHub App permission restrictions, I cannot modify workflow files. The following files need to be updated by a maintainer with workflow permissions:

• .github/workflows/backend-checks.yml: Line 21 - python-version: "3.11.6" → python-version: "3.13.5"
• .github/workflows/backend-test.yml: Line 41 - python-version: "3.11.6" → python-version: "3.13.5"

Summary:

All Docker configurations, project requirements, and tool versions have been updated to Python 3.13.5. The GitHub Actions workflows will need to be updated separately by someone with workflow modification permissions.