Add conflict for phpdocumentor/reflection-docblock v5.6.1 in composer.json (#278)

See phpDocumentor/ReflectionDocBlock#408

Author: IanDelMar

composer.json

@@ -19,6 +19,9 @@
         "szepeviktor/phpcs-psr-12-neutron-hybrid-ruleset": "^1.1.1",
         "wp-coding-standards/wpcs": "3.1.0 as 2.3.0"
     },
+    "conflict": {
+        "phpdocumentor/reflection-docblock": "5.6.1"
+    },
     "suggest": {
         "paragonie/sodium_compat": "Pure PHP implementation of libsodium",
         "symfony/polyfill-php80": "Symfony polyfill backporting some PHP 8.0+ features to lower PHP versions",