[css-contain] Remove duplicate entry in test listing

Author: frivoal

css-contain-1/Overview.bs

@@ -476,7 +476,6 @@ Layout Containment</h3>
 		contain-layout-grid-001.html
 		contain-layout-baseline-002.html
 		contain-layout-baseline-003.html
-		contain-layout-baseline-003.html
 		contain-layout-baseline-004.html
 		contain-layout-baseline-005.html
 		</wpt>