Remove sharding_column_name and sharding_column_type from vtctld2

[notfelineit]

Description

This PR removes sharding_column_name and sharding_column_type from vtctld2, as these fields are unused now. #10409 should rebase off this PR.

Related Issue(s)

#10409
#10378

Checklist

• "Backport me!" label has been added if this change should be backported
• Tests were added or are not required
• Documentation was added or is not required

Deployment Notes

[github-actions]

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[deepthi]

Not sure if this test is flaky so I re-ran it. Let's see how attempt#2 goes.

vtctld_web_test.go:132: 
[4902](https://github.com/vitessio/vitess/runs/6779853799?check_suite_focus=true#step:7:4903)
        	Error Trace:	vtctld_web_test.go:132
[4903](https://github.com/vitessio/vitess/runs/6779853799?check_suite_focus=true#step:7:4904)
        	Error:      	Expected nil, but got: &selenium.Error{Err:"no such element", Message:"no such element: Unable to locate element: {\"method\":\"tag name\",\"selector\":\"p-dropdown\"}\n  (Session info: headless chrome=90.0.4430.212)\n  (Driver info: chromedriver=90.0.4430.24 (4c6d850f087da467d926e8eddb76550aed655991-refs/branch-heads/4430@{#429}),platform=Linux 5.13.0-1025-azure x86_64)", Stacktrace:"", HTTPCode:200, LegacyCode:7}
[4904](https://github.com/vitessio/vitess/runs/6779853799?check_suite_focus=true#step:7:4905)
        	Test:       	TestCreateKs
[4905](https://github.com/vitessio/vitess/runs/6779853799?check_suite_focus=true#step:7:4906)
--- FAIL: TestCreateKs (1.34s)

[deepthi]

👍
Thank you for fixing this.

[deepthi]

Not sure what's up with the Pending Static Checks etc.. There are 2 other Static Checks etc. that passed, so merging this now.