Fix empty space in new issue pane when workspaces disabled

The execution workspace section wrapper div was rendered whenever a
project was selected, even when experimental workspaces were off.
The empty div's py-3 padding caused a visible layout bump. Now the
entire block only renders when currentProjectSupportsExecutionWorkspace
is true, and the redundant inner conditional is removed.

Co-Authored-By: Paperclip <noreply@paperclip.ing>
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

ui/src/components/NewIssueDialog.tsx

@@ -1117,9 +1117,8 @@ export function NewIssueDialog() {
           </div>
         </div>
 
-        {currentProject && (
+        {currentProject && currentProjectSupportsExecutionWorkspace && (
           <div className="px-4 py-3 shrink-0 space-y-2">
-            {currentProjectSupportsExecutionWorkspace && (
             <div className="space-y-1.5">
               <div className="text-xs font-medium">Execution workspace</div>
               <div className="text-[11px] text-muted-foreground">
@@ -1161,7 +1160,6 @@ export function NewIssueDialog() {
                 </div>
               )}
             </div>
-            )}
           </div>
         )}