Removed unnecessary type in the JSON schema

res/composer-schema.json

@@ -187,7 +187,6 @@
                     "description": "The cache max size for the files cache, defaults to \"300MiB\"."
                 },
                 "bin-compat": {
-                    "type": "string",
                     "enum": ["auto", "nosymlink", "full"],
                     "description": "The compatibility of the binaries, defaults to \"auto\" (automatically guessed) and can be \"nosymlink\" (compatible with Unix-based systems) or \"full\" (compatible with both Windows and Unix-based systems)."
                 },