vttablet: allow --init_tablet_type DRAINED

[timvaillancourt]

Description

This PR allows vttablet to start-up as DRAINED, via the existing --init_tablet_type flag

Today only REPLICA, RDONLY and SPARE are accepted, however none of these types allow a tablet to be started that is ignored by both VTOrc and VTGate. See issue for more context: #18178

Related Issue(s)

Resolves #18178

Checklist

• "Backport to:" labels have been added if this change should be back-ported to release branches
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• Documentation was added or is not required

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[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 67.54%. Comparing base (9e734f8) to head (f357690).
⚠️ Report is 118 commits behind head on main.

Additional details and impacted files

@@           Coverage Diff           @@
##             main   #18179   +/-   ##
=======================================
  Coverage   67.53%   67.54%           
=======================================
  Files        1601     1601           
  Lines      261484   261484           
=======================================
+ Hits       176592   176617   +25     
+ Misses      84892    84867   -25     

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[arthurschreiber]

Neat! We would definitely be able to make use of this too.

[github-actions]

This PR is being marked as stale because it has been open for 30 days with no activity. To rectify, you may do any of the following:

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This PR is being marked as stale because it has been open for 30 days with no activity. To rectify, you may do any of the following:

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[harshit-gangal]

@timvaillancourt There were some discussion on this in Slack. https://vitess.slack.com/archives/C02GSRZ8XAN/p1744809259637539

From there looks like we do not want the vttablet to start with drain type

[github-actions]

This PR is being marked as stale because it has been open for 30 days with no activity. To rectify, you may do any of the following:

• Push additional commits to the associated branch.
• Remove the stale label.
• Add a comment indicating why it is not stale.

If no action is taken within 7 days, this PR will be closed.

[github-actions]

This PR was closed because it has been stale for 7 days with no activity.