Updated ml-metadata build script

[vrushanaik]

Issue:

Wheel file was getting store in the working directory but the wrapper wasn't able to detect it .

Fix:

Previously, the script exited immediately after successful test execution, preventing the wrapper from detecting wheel in the working directory.

Replaced:

exit 0

With:

return 0 2>/dev/null || exit 0

This allows sourced execution to return control to the wrapper, while still exiting normally when run directly. No changes to build or test logic.

Checklist

• Have you checked and followed all the points mention in the CONTRIBUTING.MD
• Have you validated script on UBI 9 container
• Did you run the script(s) on fresh container with set -e option enabled and observe success ?
• Did you have Legal approvals for patch files ?