Fix test comments and script location

Author: gaborfeher

src/a2a/contrib/tasks/run_vertex_tests.sh tests/contrib/tasks/run_vertex_tests.shsrc/a2a/contrib/tasks/run_vertex_tests.sh renamed to tests/contrib/tasks/run_vertex_tests.sh

@@ -5,9 +5,9 @@
 unless the necessary environment variables are set, which prevents them from failing in GitHub Actions.
 
 To run these tests locally, you can use the provided script:
-    ./scripts/run_vertex_tests.sh
+    ./run_vertex_tests.sh
 
-Alternatively, you can set the environment variables manually and run pytest:
+Be sure to set the following environment variables:
     VERTEX_PROJECT="your-project" \
     VERTEX_LOCATION="your-location" \
     VERTEX_BASE_URL="your-base-url" \