🐛 Fix duplicate default value when generating CRDs with corev1.Protocol

[sbueringer]

The protocol schema was hard-coded, because of that now that the "default" marker works we are ending up with all of.

Simple example:

    // Protocol for port. Must be UDP, TCP, or SCTP.
    // Defaults to "TCP".
    // +optional
    // +default="TCP"
    Protocol corev1.Protocol `json:"protocol,omitempty" protobuf:"bytes,4,opt,name=protocol,casttype=Protocol"`

leads to

              protocol:
                allOf:
                - default: TCP
                - default: TCP
                description: |-
                  Protocol for port. Must be UDP, TCP, or SCTP.
                  Defaults to "TCP".
                type: string

This PR contains 3 commits:

• bump testdata to 1.31.0 (necessary to have the current Protocol type)
  • this one is relatively hard to review. It's easier after dropping jobTemplate (which is just an embedded type) + a bit of re-ordering
• add test coverage for protocol
• drop the embeded schema for protocol

Fixes #1027

[sbueringer]

/hold (just want to make sure there are enough reviews)

[sbueringer]

/assign @chrischdi @alvaroaleman @vincepri

[k8s-ci-robot]

LGTM label has been added.

Git tree hash: 856212f4c4f196f5b341757498aa5e8b463153ce

[k8s-ci-robot]

[APPROVALNOTIFIER] This PR is APPROVED

This pull-request has been approved by: alvaroaleman, sbueringer

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[sbueringer]

/hold cancel

Thx for the quick review!