Support no dockerfile pipeline template

[andrewballantyne]

Fixes:
https://issues.redhat.com/browse/ODC-3502

Analysis / Root cause:
Caused by #4857, and we didn't catch it because the template was already there (by the Operator at install). The cluster Christian was testing on just had no templates (for whatever reason) and thus revealed this issue.

Solution Description:
Just optional chain the property... it's not even used for this path.

Screen shots / Gifs for design review:
(no change)

Test setup:

• OpenShift Pipeline Operator installed
• No dockerfile strategy Pipeline (buildah) in the openshift namespace
• Navigate to "From Dockerfile"

Browser conformance:

• Chrome
• Firefox
• Safari
• Edge

[christianvogt]

/lgtm

[openshift-ci-robot]

[APPROVALNOTIFIER] This PR is APPROVED

This pull-request has been approved by: andrewballantyne, christianvogt

The full list of commands accepted by this bot can be found here.

The pull request process is described here

Needs approval from an approver in each of these files:

• frontend/packages/dev-console/OWNERS [andrewballantyne,christianvogt]

Approvers can indicate their approval by writing /approve in a comment
Approvers can cancel approval by writing /approve cancel in a comment