allocator: fix lease io enforcement setting typo

[kvoli]

This commit updates the "do nothing" lease IO overload enforcement (kv.allocator.lease_io_overload_threshold_enforcement) setting to be correctly spelled "ignore" rather than "ingore".

Part of: #96508

Release note (ops change): The
kv.allocator.lease_io_overload_threshold_enforcement setting value which disables enforcement is updated to be spelled correctly as "ignore" rather than "ingore".

[blathers-crl]

It looks like your PR touches production code but doesn't add or edit any test code. Did you consider adding tests to your PR?

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[cockroach-teamcity]

This change is 

[andrewbaptist]

LGTM

[kvoli]

bors r=andrewbaptist

[craig]

Build succeeded:

• Bazel Essential CI (Cockroach)

[mikeCRL]

@kvoli We're going to include 'key cluster setting changes to review' in the 23.1 GA Release Notes. I assume users do not need to worry about this if they're using the default value, but what if they've set a custom value? Will they be impacted if they don't set the value under the new name before upgrading, or is this handled automatically? Anything else to consider from a customer-impact perspective?

[kvoli]

For this change - the cluster setting was addhoed in 23.1. Users shouldn't have any value for this setting.

Are you referring to kv.allocator.replica_io_overload_threshold_enforcement? Users do need to update to a new setting if they were not using the default in 22.2.

[mikeCRL]

@kvoli Thank you. I was referring to the former. Will exclude.

As for kv.allocator.replica_io_overload_threshold_enforcement - I believe it's not a public setting so we don't have to worry about it here. Please let me know if you disagree. CC @shannonbradshaw who was looking at settings with me.