kv: remove kv.snapshot_recovery.max_rate setting

[andrewbaptist]

Fixes: #63728

There were two settings that controlled snapshot transfer rates, however, this has caused numerous problems when they are set differently as the code makes timeout assumptions based on this rate.

Epic: none

Release note: This change removes a user configurable setting
kv.snapshot_recovery.max_rate. Guidance to customers has been to
always set this equal to kv.snapshot_rebalance.max_rate and this
change will start using that setting for all snapshots. If the customer
previously set kv.snapshot_recovery.max_rate it will be cleared after
this is released and future attempts to set it will fail with:
"ERROR: unknown cluster setting 'kv.snapshot_recovery.max_rate'

[cockroach-teamcity]

This change is 

[tbg]

🙇🏽

[tbg]

Shouldn't we "Retire" that metric before just ripping it out?

cockroach/pkg/settings/common.go

Lines 96 to 101 in b39f02a

	// SetRetired marks the setting as obsolete. It also hides
	// it from the output of SHOW CLUSTER SETTINGS.
	func (c *common) SetRetired() {
	c.description = "do not use - " + c.description
	c.retired = true
	}

[tbg]

Here's an end to end example

cockroach/pkg/ts/db.go

Lines 63 to 72 in fb09177

	// deprecatedResolution30StoreDuration is retained for backward compatibility during a version upgrade.
	var deprecatedResolution30StoreDuration = func() *settings.DurationSetting {
	s := settings.RegisterDurationSetting(
	settings.TenantWritable,
	"timeseries.storage.30m_resolution_ttl", "replaced by timeseries.storage.resolution_30m.ttl",
	resolution30mDefaultPruneThreshold,
	)
	s.SetRetired()
	return s
	}()

[andrewbaptist]

Thanks! I changed to retired. and cleaned it up. It ended up being much better to use in the init function as it doesn't assign it a variable name (it is provably retired, not just a naming convention).

[andrewbaptist]

bors r=tbg

[craig]

Build succeeded:

• Bazel Essential CI (Cockroach)