Build jsinterop_annotations using an anonymous module for BCR presubmit

PiperOrigin-RevId: 788951805

Author: kevinoconnor7

.bcr/presubmit.yml

@@ -1,5 +1,4 @@
 bcr_test_module:
-  module_path: "."
   matrix:
     platform:
       - macos
@@ -11,4 +10,4 @@ bcr_test_module:
       platform: ${{ platform }}
       bazel: ${{ bazel }}
       build_targets:
-        -'//...'
+        - '@jsinterop_annotations//:all'