Update gettext/gettext requirement from ^4.8 to ^5.7

Updates the requirements on [gettext/gettext](https://github.com/php-gettext/Gettext) to permit the latest version.
- [Release notes](https://github.com/php-gettext/Gettext/releases)
- [Changelog](https://github.com/php-gettext/Gettext/blob/master/CHANGELOG.md)
- [Commits](php-gettext/Gettext@v4.8.0...v5.7.3)

---
updated-dependencies:
- dependency-name: gettext/gettext
  dependency-type: direct:production
...

Signed-off-by: dependabot[bot] <[email protected]>

composer.json

@@ -12,7 +12,7 @@
     ],
     "require": {
         "eftec/bladeone": "3.52",
-        "gettext/gettext": "^4.8",
+        "gettext/gettext": "^5.7",
         "mck89/peast": "^1.13.11",
         "wp-cli/wp-cli": "^2.12"
     },