Restore updates to changes.xliff (#19482)
Fixes #19463
### Summary of the issue:
a job failed because `<!-- markdownlint-disable -->` was no longer
handled properly https://github.com/nvaccess/nvda/pull/19308 . This
committed and pushed a bad xliff file, causing subsequent runs to fail.
### Description of user facing changes:
translators now have an updated version of the changes file
### Description of developer facing changes:
None
### Description of development approach:
- Reverted bad update to xliff performed in
[nvaccess/nvda/actions/runs/20052703912/job/57511814365](https://github.com/nvaccess/nvda/actions/runs/20052703912/job/57511814365)
- Removed bad xliff line which contained the markdownlint comment
Included `$PSNativeCommandUseErrorActionPreference = $true` in the
"update xliff files" job. This makes PowerShell treat non-zero exit
codes as errors. By default it is set to `$false`, which means
PowerShell ignores the exit code.
### Testing strategy:
Tested running `python source/markdownTranslate.py updateXliff -x
user_docs/en/changes.xliff -m user_docs/en/changes.md -o
user_docs/en/changes.xliff.tmp`
Extracted the PowerShell code from
`.github/workflows/regenerate_english_userDocs_translation_source.yml`
into a standalone script, hardcoded to update based on `HEAD~10`. Ran
the script without changes and observed the problem; applied the change
to `$PSNativeCommandUseErrorActionPreference` and reran, and observed
that the job was aborted when python exited with code 1.
### Known issues with pull request:
None
