Deprecate store_capabilities_update_min_interval

Includes a release note.

Change-Id: Ic25549ac022cf7fc93affc331f2379ea63bf6fb2
Implements: blueprint spec-lite-deprecate-update-min-interval

glance_store/backend.py

@@ -91,6 +91,16 @@ Related Options:
     cfg.IntOpt('store_capabilities_update_min_interval',
                default=0,
                min=0,
+               deprecated_for_removal=True,
+               deprecated_since='Rocky',
+               deprecated_reason=_("""
+This option configures a stub method that has not been implemented
+for any existing store drivers.  Hence it is non-operational, and
+giving it a value does absolutely nothing.
+
+This option is scheduled for removal early in the Stein development
+cycle.
+"""),
                help=_("""
 Minimum interval in seconds to execute updating dynamic storage
 capabilities based on current backend status.
@@ -106,7 +116,7 @@ of the store is triggered.
 By default, this option is set to zero and is disabled. Provide an
 integer value greater than zero to enable this option.
 
-NOTE: For more information on store capabilities and their updates,
+NOTE 1: For more information on store capabilities and their updates,
 please visit: https://specs.openstack.org/openstack/glance-specs/\
 specs/kilo/store-capabilities.html
 
@@ -115,6 +125,11 @@ deployment and help with the usage of this feature, please contact
 the storage driver maintainers listed here:
 https://docs.openstack.org/glance_store/latest/user/drivers.html
 
+NOTE 2: The dynamic store update capability described above is not
+implemented by any current store drivers.  Thus, this option DOES
+NOT DO ANYTHING (and it never has).  It is DEPRECATED and scheduled
+for removal early in the Stein development cycle.
+
 Possible values:
     * Zero
     * Positive integer

releasenotes/notes/deprecate-store_capabilities_update_min_interval-039389fa296e2494.yaml

@@ -0,0 +1,14 @@
+---
+deprecations:
+  - |
+    The glance_store configuration option
+    ``store_capabilities_update_min_interval`` is deprecated in this
+    release and is subject to removal at the beginning of the Stein
+    development cycle, following the `OpenStack standard deprecation policy
+    <https://governance.openstack.org/reference/tags/assert_follows-standard-deprecation.html>`_.
+
+    The option configures a stub method that has not been implemented
+    for any existing store drivers.  Hence it is non-operational.  Given
+    that it has *never* been operational, it will not be missed.  Its
+    presence is confusing to operators and thus it is hereby deprecated
+    for removal.