fix: Fix the icon of pipeline template

Created by: harrisonliu5

Signed-off-by: harrisonliu5 harrisonliu@kubesphere.io

What type of PR is this?

What this PR does / why we need it:

Which issue(s) this PR fixes:

Fixes #https://github.com/kubesphere/ks-devops/issues/501

Special notes for reviewers:

Does this PR introduced a user-facing change?

None

Additional documentation, usage docs, etc.: