Fix tiddler info area content bleeding on close animation (#5453)

themes/tiddlywiki/vanilla/base.tid

@@ -995,6 +995,7 @@ button.tc-btn-invisible.tc-remove-tag-button {
 {{$:/themes/tiddlywiki/vanilla/sticky}}
 
 .tc-tiddler-info {
+	overflow: hidden;
 	padding: 14px 42px 14px 42px;
 	background-color: <<colour tiddler-info-background>>;
 	border-top: 1px solid <<colour tiddler-info-border>>;