ext/standard: "double" is not deprecated for settype() (#20694)

Remove incorrect inline comment that using "double" as the type is deprecated;
this comment was added in 929ae94 when support
for "float" was included, but the use of "double" was never actually
deprecated.

[skip ci]

Author: DanielEScherzer

ext/standard/type.c

@@ -105,7 +105,7 @@ PHP_FUNCTION(settype)
 		convert_to_long(ptr);
 	} else if (zend_string_equals_ci(type, ZSTR_KNOWN(ZEND_STR_FLOAT))) {
 		convert_to_double(ptr);
-	} else if (zend_string_equals_ci(type, ZSTR_KNOWN(ZEND_STR_DOUBLE))) { /* deprecated */
+	} else if (zend_string_equals_ci(type, ZSTR_KNOWN(ZEND_STR_DOUBLE))) {
 		convert_to_double(ptr);
 	} else if (zend_string_equals_ci(type, ZSTR_KNOWN(ZEND_STR_STRING))) {
 		convert_to_string(ptr);