build: update to bazel 6

This is necessary for an incremental migration to `rules_js` which
requires Bazel v6. Bazel v6 removed the managed directories feature,
which means we no longer can rely on symlinked node modules as the Bazel
repository; but rather need to duplicate dependencies. This is
okay/acceptable to enable the incremental migration.

Author: devversion

Diff for: .bazelversion

@@ -1 +1 @@
-5.0.0
+6.5.0

Diff for: WORKSPACE

@@ -1,7 +1,6 @@
 #Workspace for angular material
 workspace(
     name = "angular_material",
-    managed_directories = {"@npm": ["node_modules"]},
 )
 
 # Point to the nested WORKSPACE we merged from github.com/angular/material.angular.io
@@ -103,9 +102,6 @@ yarn_install(
     manual_build_file_contents = create_npm_package_archive_build_file(),
     package_json = "//:package.json",
     quiet = False,
-    # We prefer to symlink the `node_modules` to only maintain a single install.
-    # See https://github.com/angular/dev-infra/pull/446#issuecomment-1059820287 for details.
-    symlink_node_modules = True,
     yarn = "//:.yarn/releases/yarn-1.22.17.cjs",
     yarn_lock = "//:yarn.lock",
 )