chore: fix the output of etcdctl watch -i

[JalinWang]

Please read https://github.com/etcd-io/etcd/blob/main/CONTRIBUTING.md#contribution-flow.

Although the interactive mode of etcdctl watch supports progress command now, the output is a little bit out-of-date :(

[k8s-ci-robot]

[APPROVALNOTIFIER] This PR is NOT APPROVED

This pull-request has been approved by: JalinWang
Once this PR has been reviewed and has the lgtm label, please assign serathius for approval. For more information see the Code Review Process.

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

Needs approval from an approver in each of these files:

• OWNERS

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

[k8s-ci-robot]

Hi @JalinWang. Thanks for your PR.

I'm waiting for a etcd-io member to verify that this patch is reasonable to test. If it is, they should reply with /ok-to-test on its own line. Until that is done, I will not automatically test new commits in this PR, but the usual testing commands by org members will still work. Regular contributors should join the org to skip this step.

Once the patch is verified, the new status will be reflected by the ok-to-test label.

I understand the commands that are listed here.

Instructions for interacting with me using PR comments are available here. If you have questions or suggestions related to my behavior, please file an issue against the kubernetes-sigs/prow repository.

[codecov]

Codecov Report

Attention: Patch coverage is 0% with 2 lines in your changes missing coverage. Please review.

Project coverage is 68.88%. Comparing base (fefce54) to head (76065c1).
Report is 25 commits behind head on main.

Files with missing lines	Patch %	Lines
etcdctl/ctlv3/command/watch_command.go	0.00%	2 Missing ⚠️

Additional details and impacted files

Files with missing lines	Coverage Δ
etcdctl/ctlv3/command/watch_command.go	44.08% <0.00%> (ø)

... and 23 files with indirect coverage changes

@@            Coverage Diff             @@
##             main   #19397      +/-   ##
==========================================
- Coverage   68.94%   68.88%   -0.06%     
==========================================
  Files         420      420              
  Lines       35759    35764       +5     
==========================================
- Hits        24654    24637      -17     
- Misses       9684     9705      +21     
- Partials     1421     1422       +1     

---

Continue to review full report in Codecov by Sentry.

Legend - Click here to learn more
Δ = absolute <relative> (impact), ø = not affected, ? = missing data
Powered by Codecov. Last update fefce54...76065c1. Read the comment docs.

[ivanvc]

/ok-to-test

[ivanvc]

Thanks for the pull request, @JalinWang. Please take a look at my comment :)

[ivanvc]

I'd like to suggest having the same message in both places for consistency (and use the opportunity to improve the grammar :). i.e.,

Suggested change

	fmt.Fprintf(os.Stderr, "Invalid command %s (only support `watch` & `progress`)\n", l)
	fmt.Fprintf(os.Stderr, `Invalid command %s (only "watch" and "progress" are supported)\n`, l)

And apply the same to line 108.

[k8s-ci-robot]

@JalinWang: The following test failed, say /retest to rerun all failed tests or /retest-required to rerun all mandatory failed tests:

Test name	Commit	Details	Required	Rerun command
pull-etcd-e2e-amd64	76065c1	link	true	/test pull-etcd-e2e-amd64

Full PR test history. Your PR dashboard. Please help us cut down on flakes by linking to an open issue when you hit one in your PR.

Instructions for interacting with me using PR comments are available here. If you have questions or suggestions related to my behavior, please file an issue against the kubernetes-sigs/prow repository. I understand the commands that are listed here.