Remove unused attachments line remaining from older refactor

Commit 56ba745 replaced the AttachmentsForm method block in
/RTIR/Create.html with /Ticket/Elements/AddAttachments, and updated the
parallel call in Incident/Elements/Create, but missed this one in
Investigation/Elements/Create. It has gone unnoticed because
the only caller (Incident/Create.html) always skips it.

Author: cbrandtbuffalo

html/RTIR/Incident/Create.html

@@ -329,7 +329,7 @@
     QueueObj => $InvestigationsQueueObj,
     Lifecycle => RT::IR->lifecycle_investigation,
     Constituency => $constituency,
-    SkipField => { Owner => 1, Attachments => 1, DateFields => 1 },
+    SkipField => { Owner => 1, DateFields => 1 },
     IncludeSignature => (exists $ARGS{'InvestigationContent'} ? 0 : 1),
 &>
 </div>

html/RTIR/Investigation/Elements/Create

@@ -285,10 +285,6 @@
   &>
 % }
 
-% unless ( $SkipField{'Attachments'} ) {
-<& /RTIR/Create.html:AttachmentsForm &>
-% }
-
 </&>
 
 <div class="form-row">