## The basics
- [x] I [validated my changes](https://developers.google.com/blockly/guides/contribute/core#making_and_verifying_a_change)
## The details
### Resolves
N/A (no tracking issue)
### Proposed Changes
Introduces a GitHub actions CI workflow to run the webdriver IO tests from https://github.com/google/blockly-keyboard-experimentation as part of core Blockly's CI.
### Reason for Changes
Since development on the plugin is going to continue for many months yet, this ensures that behavioral changes in core Blockly don't inadvertently break the plugin.
Note that this shouldn't be made a blocking workflow since there may be cases where it's necessary to break the plugin before a change to the plugin itself can be introduced to then fix it (as this has happened many times in the past). However, the CI check is forced signal to both author and reviewer as to whether their change affects the plugin without having to manually check the test suite.
### Test Coverage
N/A -- Verifying that the CI workflow runs is sufficient.
### Documentation
No documentation changes are needed here.
### Additional Information
Nothing.
