ci: raise workspace runtimes to Python 3.12

[Jammy2211]

Overview

Complete Phase 5B of the ecosystem Python 3.12 migration by raising the deployment runtime selector in the three user workspaces and three HowTo repositories. This is a coordinated six-line metadata change; it is intentionally held as one batch until every target repository is free.

Plan

• Change all six root runtime.txt files to exactly python-3.12.1.
• Preserve a terminating newline in each file.
• Make no script, notebook, dependency, documentation, or workflow changes.
• Validate the six exact values and git diff --check; do not repeat ecosystem tests for deployment-selector lines.

Detailed implementation plan

Affected Repositories

• autofit_workspace (primary)
• autogalaxy_workspace
• autolens_workspace
• HowToFit
• HowToGalaxy
• HowToLens

Branch Survey

Repository	Current Branch	Dirty?	Current runtime
./autofit_workspace	main	clean	python-3.10
./autogalaxy_workspace	main	clean	python-3.11
./autolens_workspace	main	clean	python-3.11
./HowToFit	main	clean	python-3.11
./HowToGalaxy	main	clean	python-3.11
./HowToLens	main	clean	python-3.11

Suggested branch: feature/python-312-workspace-runtime-pins

Implementation Steps

1. Wait for extra-galaxies-multi-galaxy to release its active autogalaxy_workspace claim; do not split the batch or overlap that task.
2. Create one task worktree containing all six repositories from their current origin/main heads.
3. Replace each root runtime.txt content with python-3.12.1 plus a newline.
4. Verify all six exact values and run git diff --check in each repository.
5. Open one pending-release PR per repository under the same task branch.

Key Files

• autofit_workspace/runtime.txt
• autogalaxy_workspace/runtime.txt
• autolens_workspace/runtime.txt
• HowToFit/runtime.txt
• HowToGalaxy/runtime.txt
• HowToLens/runtime.txt

Sizing Decision

The Feature Agent scored this too-large solely from six-repository and migration/test keywords. That proxy is overridden: the implementation is six identical one-line metadata edits with no API, script, notebook, or generated-artifact impact.

Original Prompt

Click to expand starting prompt

Ok, lets remove support for anything below python3.12, do a census to make sure we simplify requriements, build server, testing, etc. Also make sure all docs are updated.

[Jammy2211]

Phase 5B executed 2026-07-30 — all six repositories came free (the autogalaxy_workspace and autolens_workspace claims cleared), so the batch ran as planned.

Six one-line PRs, one per repository, each setting the root runtime.txt to exactly python-3.12.1 with a terminating newline:

• Raise deployment runtime to python-3.12.1 (Phase 5B) #128 (was python-3.10)
• Raise deployment runtime to python-3.12.1 (Phase 5B) autogalaxy_workspace#189 (was python-3.11)
• Raise deployment runtime to python-3.12.1 (Phase 5B) autolens_workspace#399 (was python-3.11)
• Raise deployment runtime to python-3.12.1 (Phase 5B) HowToFit#40 (was python-3.11)
• Raise deployment runtime to python-3.12.1 (Phase 5B) HowToGalaxy#51 (was python-3.11)
• Raise deployment runtime to python-3.12.1 (Phase 5B) HowToLens#63 (was python-3.11)

Validation (intentionally narrow per the task prompt): exact-value census across all six files plus git diff --check — all clean. No script/notebook/dependency/workflow changes.

Awaiting human merge; branches live in the python-312-workspace-runtime-pins task worktree.

[Jammy2211]

Phase 5B merged 2026-07-30 — all six runtime.txt PRs merged unchanged (merge trees byte-identical to the pushed heads), CI green everywhere:

autofit_workspace#128 · autogalaxy_workspace#189 · autolens_workspace#399 · HowToFit#40 · HowToGalaxy#51 · HowToLens#63

Canonical checkouts fast-forwarded, task worktree and branches removed, completion recorded at PyAutoMind/complete/2026/07/python-312-workspace-runtime-pins.md. Every tracked Python selector in the ecosystem is now at 3.12+. Leaving this issue (and parent PyAutoNerves#142) open for explicit human close.

[Jammy2211]

All six runtime.txt PRs merged unchanged 2026-07-30 (autofit_workspace#128 et al.); record complete/2026/07/python-312-workspace-runtime-pins.md. python-312-floor arc complete (record: PyAutoMind/complete/2026/07/python-312-floor.md; parent PyAutoNerves#142 closed). Closing on the same 2026-07-30 human cleanup authorization.