fix: Pipeline editor cant save init value

Created by: Mrxyy

What type of PR is this?

/kind bug

What this PR does / why we need it:

When the pipeline is edited again and no input is made, the initial value cannot be saved

Which issue(s) this PR fixes:

Fixes ##https://github.com/kubesphere/kubesphere/issues/3950

Special notes for reviewers:

Does this PR introduced a user-facing change?

None

Additional documentation, usage docs, etc.: