[ci] Pull-request test: update the selector of the button for extensi…

[zoe-translates]

…ons.

This should fix the recent CI failures. The element's id is now "btn-extensions-value".

[zoe-translates]

For the interested: the change was introduced in chromium/chromium@27b2842

[zoe-translates]

See also zotero/translate#20. Because of that issue, the Selenium test here doesn't seem to test what it is supposed to test.

[zoe-translates]

The series of issues that render the Selenium test invalid.

• This one: Selector update for the button for extensions in chrome://system.
• Translator tester: running URL-specified translator(s) does not do what it is supposed to do (not awaiting translators to fully load) translate#20: In the testing tool (enabled by debug build of Zotero Connector), the URL-specified tests do not run.
• Testing: Fix failure to run non-web translators' tests in debug build. zotero-connectors#429: Only web translators' tests are run in the debug build.

Consequently, our current CI script for testing pull requests...

translators/.ci/pull-request-check/check-pull-request.sh

Lines 36 to 37 in 3a9544d

	get_translators_to_check
	./selenium-test.js "$TRANSLATORS_TO_CHECK"

• Cannot be run on the recent versions of Google Chrome by Selenium
  • ❌ The immediate cause of recent PR test failures.
• Even when the Chrome compatibility wasn't an issue, the tests for the modified translator(s) in the PR were not actually run in the testing tool, because the tool silently skip the translators identified in the URL.
  • ✅ So the previous PR test successes were false negatives.
• For non-web translators, the test will still fail by timeout (false positives), because the translator testing tool itself does not actually run any non-web tests.

[AbeJellinek]

Thank you!