Improve file header on mobile (#19945)

- File headers can become quite width, so ensure the file size is not
being wrapped into itself(width + padding-right) and allow the overflow
to be scrolled(overflow-x).

web_src/less/_repository.less

@@ -3048,9 +3048,10 @@ td.blob-excerpt {
 }
 
 .file-header {
+  align-items: center;
   display: flex;
   justify-content: space-between;
-  align-items: center;
+  overflow-x: scroll;
   padding: 8px 12px !important;
 }
 
@@ -3062,6 +3063,7 @@ td.blob-excerpt {
 .file-info-entry {
   display: flex;
   align-items: center;
+  width: max-content;
 }
 
 .file-info-entry + .file-info-entry {