Remove unused flex-grow CSS rule

Author: GuillaumeGomez

src/librustdoc/html/static/css/rustdoc.css

@@ -539,13 +539,11 @@ ul.block, .block li {
 
 .rustdoc .example-wrap > pre {
 margin: 0;
-flex-grow: 1;
 overflow-x: auto;
 }
 
 .rustdoc .example-wrap > pre.example-line-numbers,
 .rustdoc .example-wrap > pre.src-line-numbers {
-flex-grow: 0;
 overflow: initial;
 text-align: right;
 -webkit-user-select: none;