main: run respec workflow only on changes to relevant files

[ralfhandl]

Getting tired of re-reviewing spec publishing PRs on every change to unrelated files on main:

• only run the respec workflow if itself, one of its scripts, or one of its inputs change
• filter out "random" changes to the produced HTML
• filter out ReSpec minor & patch version part - it changes more often than we publish specs

Tick one of the following options:

• schema changes are included in this pull request
• schema changes are needed for this pull request but not done yet
• no schema changes are needed for this pull request

[duncanbeevers]

@ralfhandl Would you link to one of these spurious spec publishing PRs?
I would expect unrelated changes to be a no-op, and if they triggered a PR that it would be free of any changes.
Are there non-deterministic outputs from the respec workflow?

[ralfhandl]

@duncanbeevers For example #4412.

Opened three weeks ago, still unmerged because it did not get a second approval, refreshed several times due to merges into main, almost every refresh dismissed one of my approvals.

Now I'll wait for someone else to approve first and hope that I can approve second and immediately merge before the next refresh dismisses the first review.

[ralfhandl]

Are there non-deterministic outputs from the respec workflow?

Unfortunately there are seemingly random flip-flop changes that have no visible effect that I can spot.

Some seem to be related to the time-of-day on the server and dark mode.

Another is whether the table of contents is inlined, which should only depend on the width of the browser window, and that width should be deterministic for the head-less puppeteer browser.

[ralfhandl]

@duncanbeevers Thanks for asking, it got me thinking: we anyway tweak the respec output to avoid breaking Google Analytics, so why not also filter out the known non-deterministic things.

[duncanbeevers]

I see there are changes in here to make the output more stable. I think those changes should be landed first / independently.

[duncanbeevers]

Consider using the TZ env var while running npx respec to ensure more-consistent output, regardless of where the workflow / script is run.

TZ=UTC npx respec …

[ralfhandl]

Interesting idea. Did you test whether it has the desired effect for the fluctuating darkmode?

[ralfhandl]

@duncanbeevers I think these are fine in one PR:

• make the output more stable
• avoid unnecessary Github workflow runs