Editorial: remove "may" from statements of fact

source

@@ -7794,7 +7794,7 @@ interface <dfn>DOMStringList</dfn> {
   form, represented here as a <span>Record</span>. This serialized form has all the information
   necessary to later deserialize into a new JavaScript value in a different Realm.</p>
 
-  <p>This process may throw an exception, for example when trying to serialize un-serializable
+  <p>This process can throw an exception, for example when trying to serialize un-serializable
   objects.</p>
 
   <ol>
@@ -8157,7 +8157,7 @@ o.myself = o;</pre>
   <var>serialized</var>, which was previously produced by <span>StructuredSerialize</span>, and
   deserializes it into a new JavaScript value, created in <var>targetRealm</var>.</p>
 
-  <p>This process may throw an exception, for example when trying to allocate memory for the new
+  <p>This process can throw an exception, for example when trying to allocate memory for the new
   objects (especially <code data-x="">ArrayBuffer</code> objects).</p>
 
   <ol>