Release 2.1.6

[github-actions[bot]]

Checklist

1. [x] Check if the version, base, and target branches are as you desire.
2. [x] Make sure you have woorelease installed and set up.
3. [x] Go to your local repo clone, and check out this PR to be able to commit any potential adjustments.

   git fetch origin release/2.1.6
   git checkout release/2.1.6

4. [x] Remove older changelog entries from readme.txt (keep the last two versions, since we will be adding a third during the release), commit changes.
5. [x] Simulate the release locally

   woorelease simulate --product_version=2.1.6  --wc_tested=9.2 --generate_changelog https://github.com/woocommerce/woocommerce-google-analytics-integration/tree/release/2.1.6

   Note: Select y when prompted: "Would you like to add/delete them in the svn working copy?"

6. [x] The changelog is correct. Check if some entries are missing, need rewording, or need to be deleted. You can edit respective PRs by changing their title, ### Changelog entry section, or assigning the changelog: none label. You can also edit the changelog manually in the woorelease release step later.
7. [x] Automated tests are passing.
8. [x] Test the package
   1. [x] Install the /tmp/woocommerce-google-analytics-integration.zip file on a test site
   2. [x] Confirm it activates without warnings/errors and is showing the right versions
   3. [x] Run a few basic smoke tests

Next steps

1. [x] Do the final release

   woorelease release --product_version=2.1.6  --wc_tested=9.2  --generate_changelog https://github.com/woocommerce/woocommerce-google-analytics-integration/tree/release/2.1.6

   When prompted for changelog entries, double-check and apply any changes if needed.

2. [x] Confirm the release using the activation link from your email. When releasing to WordPress.org, “release notifications” have been enabled, so each committer will be sent an email with an action link to confirm the release. This must be done after committing in SVN before the release becomes available. See the following page for releases pending notifications: https://wordpress.org/plugins/developers/releases/
3. [x] Go to https://github.com/woocommerce/woocommerce-google-analytics-integration/releases/2.1.6, generate GitHub release notes, and paste them as a comment here.
4. [x] Merge this PR after the new release is successfully created and the version tags are updated.
5. [ ] Merge trunk to develop (PR), if applicable for this repo.
6. [ ] Update documentation
   • [ ] Publish any new required docs
   • [ ] Update triggers/rules/actions listing pages
7. [ ] Mark related ideas complete on the feature requests page.

[eason9487]

What's Changed

Developer-facing changes 🧑‍💻

• Update #billing-state locator to fix failing E2E test by @martynmjones in https://github.com/woocommerce/woocommerce-google-analytics-integration/pull/453
• Make the value entering of the billing state field in e2e test compatible with WC < 9.2 by @eason9487 in https://github.com/woocommerce/woocommerce-google-analytics-integration/pull/457