cleanup(build): some bazel related cleanup

- Ensures that `bazel build ...` succeeds
- Removed unused dep in e2e-app
- Updates rules_sass

Author: mmalerba

.bazelignore

@@ -1 +1,3 @@
 node_modules
+tools/dashboard/node_modules
+tools/dashboard/functions/node_modules

WORKSPACE

@@ -12,9 +12,9 @@ http_archive(
 # Add sass rules
 http_archive(
   name = "io_bazel_rules_sass",
-  sha256 = "f71709f4c2d39e81c9b452e00f22e554b26d7beacaedc5b85d61f771fd01268d",
-  url = "https://github.com/bazelbuild/rules_sass/archive/1.16.1.zip",
-  strip_prefix = "rules_sass-1.16.1",
+  sha256 = "ea79647e5cd36867568d80811a951c7b3170791058f50a5cbd3d542627e78881",
+  url = "https://github.com/bazelbuild/rules_sass/archive/1.17.3.zip",
+  strip_prefix = "rules_sass-1.17.3",
 )
 
 load("@build_bazel_rules_nodejs//:defs.bzl", "check_bazel_version", "node_repositories", "yarn_install")

src/e2e-app/BUILD.bazel

@@ -15,7 +15,6 @@ ng_module(
     "@npm//@angular/platform-browser",
     "@npm//@angular/router",
     "@npm//@angular/animations",
-    "@npm//@webcomponents/custom-elements",
     "//src/cdk/drag-drop",
     "//src/cdk/overlay",
     "//src/cdk/scrolling",

tools/highlight-files/BUILD.bazel

@@ -8,12 +8,14 @@ ts_library(
   srcs = glob(["**/*.ts"]),
   deps = [
     "@npm//@types/node",
+    "@npm//highlight.js",
   ],
   tsconfig = ":tsconfig.json",
 )
 
 nodejs_binary(
   name = "highlight-files",
+  node_modules = "@npm//:node_modules",
   entry_point = "angular_material/tools/highlight-files/highlight-files.js",
   data = [
     "@npm//highlight.js",