Fixes misspellings identified by the [check-spelling
action](https://github.com/marketplace/actions/check-spelling).
The misspellings have been reported at
https://github.com/jsoref/playwright/actions/runs/10015023629#summary-27685777352
The action will report that the changes in this PR would make it happy:
https://github.com/jsoref/playwright/actions/runs/10015023971#summary-27685778305
---
I understand that the commit messages will need to be reworded to match
house style. For the time being, these are merely noting the changes
they contain so that when I rebase or need to drop things, I can. --
I've already rebased once as someone fixed one of the items that my
draft work was going to fix.
---
## Testing
* The tests _mostly_ passed when I managed to trigger them, but there
were a handful of things that I didn't quite understand
* There are a large number of warnings relating to a bad interaction
between any workflow that uses this local action
b535139b32/.github/actions/run-test/action.yml (L74-L80)
and the action it calls -- I've opened Azure/login#474 asking them to
refactor their action so that it doesn't cause so much noise while
running this repository's tests
* I'm vaguely curious as to why this repository has a `branch`
constraint for its `pull_request` events in its workflows -- that
constraint gave me a number of additional headaches while trying to
prepare this branch for this PR.
---------
Signed-off-by: Josh Soref <2119212+jsoref@users.noreply.github.com>
Previously, we were guessing whether something is optional from the
comment (looking for stuff like "defaults to" or "optional").
To remove this error-prone technique, every optional property or
argument (but not option) is explicitly marked with "?".
