Bug Fix: Record CI step outcomes for the PR test summary

[alisonscheng]

The PR test summary posted ❓ for every check on PR #73. GitHub's jobs
API returned an empty steps array for that run's test job, even after
a re-run, so the summary couldn't find any of the steps it looks up by
name. (This may be a bug on Github's side, according to Claude)

The test workflow now records the lint, format, build and test step
outcomes in step-outcomes.json and uploads it with the other test
files. The summary reads that file first and calls the jobs API only
if the file is missing, so it will run independently if the github jobs api is down or not.

Lint and format statuses use each step's outcome, so they still show
a failure when continue-on-error lets the job carry on.

Also: I upgraded the actions versions and pinned the ubuntu version to get rid of the node and ubuntu warnings.

[github-actions]

✅ Test Results

All tests passed!

Complete Test Suite Coverage:

• ❓ Buttons - Button, ButtonIconOnly, ButtonWithIcon, ButtonCopyToClipboard
• ❓ Inputs - InputCheckBox, InputNumber, InputEnumBoxRounded, InputStringBoxRounded
• ❓ Plots - PlotlyHeatmap, PlotlyHeatmapTiled, PlotlyScatter, Histogram, ColormapPicker
• ❓ Layout - Sidebar, SidebarItem, FinchSidebar, FinchAppLayout, FinchHeader, FinchMainContent, Header, Main, Bento, Paper, Widget
• ❓ Tiled - TiledComponents, TiledLinePlotMaker
• ❓ Devices - Camera, Shutter, DeviceControllerBox, DeviceControllerBoxSimple, TableDeviceController, ControllerAbsoluteMove, ControllerRelativeMove, Hexapod, BeamEnergy
• ❓ Services - QueueServer, SignalMonitorPlots, Experiment
• ❓ Misc - IFrame, GoogleDoc, SelectDropdown, ComponentViewer, ComponentViewerUtils

Test Environment: Node.js 20.x
Linting: ❓ ESLint status unknown
Formatting: ❓ Formatting status unknown
Type Checking: ❓ Build status unknown
Build: ❓ Production build successful
Tests: ❓ Test status unknown

[SeijDeLeon]

lgtm