Update browser-ui-test version to 0.9.0

Author: GuillaumeGomez

src/ci/docker/host-x86_64/x86_64-gnu-tools/browser-ui-test.version

@@ -1 +1 @@
-0.8.5
+0.9.0

src/tools/rustdoc-gui/tester.js

@@ -138,7 +138,6 @@ async function main(argv) {
     try {
         // This is more convenient that setting fields one by one.
         let args = [
-            "--no-screenshot-comparison",
             "--variable", "DOC_PATH", opts["doc_folder"],
         ];
         if (opts["debug"]) {