[ja] Update page weights under content/ja/docs/reference.

[s-kawamura-w664]

This PR updates the page weights under content/ja/docs/reference.
This updates the page order.

Related: #37717

Only the following file was already set in #29847.

• content/ja/docs/reference/kubectl/cheatsheet.md

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[s-kawamura-w664]

content/ja/docs/reference/kubenet/overview.md was removed from en.
But there are still left in ja.
The page's contents would need to be moved to _index.md.
This PR is purpose to update weights, so another PR is needed.
Related: #29847

[t-inu]

/lgtm

[k8s-ci-robot]

LGTM label has been added.

Git tree hash: fbe4cfd2866a56f9167d6627848ffbde40f55158

[s-kawamura-w664]

/assign @nasa9084 @inductor
Could you confirm for approval.

[nasa9084]

/approve

[k8s-ci-robot]

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