Description of problem:

Unable to uncheck the optional workspace checkbox in pipeline builder after it is checked

Prerequisites (if any, like setup, operators/versions):

Steps to Reproduce

1. Goto Pipeline builder
2. switch to yaml view and try one of the samples
3. switch back to form view and in the workspaces section check the `optional workspace` checkbox
4. try to uncheck the box

Actual results:

Unable to uncheck it

Expected results:

Should able to uncheck it

Reproducibility (Always/Intermittent/Only Once):

Build Details: 

4.8.0-0.nightly-2021-06-13-101614

Additional info: