ci: fix Gherkin compatibility by pinning behat/gherkin < 4.9

- Pin behat/gherkin to < 4.9 to fix i18n.php path issue with Codeception 4.x
- Add gherkin: [] to codeception.dist.yml as extra safeguard
- Update deprecated GitHub Actions to v4
- Fix deprecated set-output syntax

Author: jasonbahl

composer.json

@@ -17,6 +17,7 @@
       }
     },
     "require-dev": {
+        "behat/gherkin": "<4.9",
         "wp-graphql/wp-graphql-testcase": "*",
         "squizlabs/php_codesniffer": "^3.6",
         "phpcompatibility/phpcompatibility-wp": "*",