Update constants.xml Fix typo (#4216)

Author: mmalferov

reference/dom/constants.xml

@@ -262,7 +262,7 @@
        Error code not part of the DOM specification. Meant for PHP errors.
        Deprecated as of PHP 8.4.0 because this is no longer used.
        Prior to PHP 8.4.0, this was inconsistently used to indicate
-       our-of-memory situations.
+       out-of-memory situations.
       </entry>
      </row>
      <row xml:id="constant.dom-index-size-err">