Add deprecation notice for multi_region_auxiliary field in BQ reservation (#11220) (#18803)

[upstream:4f0795e8d59c162bef7d179cc4212d54af33e2c7]

Signed-off-by: Modular Magician <[email protected]>

Author: modular-magician

.changelog/11220.txt

@@ -0,0 +1,3 @@
+```release-note:deprecation
+bigqueryreservation: deprecated `multi_region_auxiliary` on `google_bigquery_reservation`.
+```

google/services/bigqueryreservation/resource_bigquery_reservation.go

@@ -116,8 +116,9 @@ Examples: US, EU, asia-northeast1. The default value is US.`,
 				Default: "US",
 			},
 			"multi_region_auxiliary": {
-				Type:     schema.TypeBool,
-				Optional: true,
+				Type:       schema.TypeBool,
+				Optional:   true,
+				Deprecated: "`multi_region_auxiliary` is deprecated and will be removed in a future major release. This field is no longer supported by the BigQuery Reservation API.",
 				Description: `Applicable only for reservations located within one of the BigQuery multi-regions (US or EU).
 If set to true, this reservation is placed in the organization's secondary region which is designated for disaster recovery purposes. If false, this reservation is placed in the organization's default region.`,
 			},

website/docs/r/bigquery_reservation.html.markdown

@@ -81,10 +81,12 @@ The following arguments are supported:
   Maximum number of queries that are allowed to run concurrently in this reservation. This is a soft limit due to asynchronous nature of the system and various optimizations for small queries. Default value is 0 which means that concurrency will be automatically set based on the reservation size.
 
 * `multi_region_auxiliary` -
-  (Optional)
+  (Optional, Deprecated)
   Applicable only for reservations located within one of the BigQuery multi-regions (US or EU).
   If set to true, this reservation is placed in the organization's secondary region which is designated for disaster recovery purposes. If false, this reservation is placed in the organization's default region.
 
+  ~> **Warning:** `multi_region_auxiliary` is deprecated and will be removed in a future major release. This field is no longer supported by the BigQuery Reservation API.
+
 * `edition` -
   (Optional)
   The edition type. Valid values are STANDARD, ENTERPRISE, ENTERPRISE_PLUS