[ DDS ] Normalize workspace path for uri_converter_test.dart

Fixes #55411

Change-Id: I7b5d2405f9d0479900046bf924cc0d26a1eec545
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/362040
Commit-Queue: Ben Konyi <[email protected]>
Reviewed-by: Derek Xu <[email protected]>
Reviewed-by: Ben Konyi <[email protected]>

Author: bkonyi

pkg/dds/test/uri_converter_test.dart

@@ -84,7 +84,7 @@ void main() {
       Uri serviceUri = remoteVmServiceUri;
       dds = await DartDevelopmentService.startDartDevelopmentService(
         remoteVmServiceUri,
-        uriConverter: BazelUriConverter('/workspace/root/').uriToPath,
+        uriConverter: BazelUriConverter('/workspace/root').uriToPath,
       );
       serviceUri = dds!.wsUri!;
       expect(dds!.isRunning, true);