chore(main): release google-cloud-spanner-v1 1.15.0 (#32802)

* chore(main): release google-cloud-spanner-v1 1.15.0

* 🦉 Updates from OwlBot post-processor

See https://github.com/googleapis/repo-automation-bots/blob/main/packages/owl-bot/README.md

---------

Co-authored-by: release-please[bot] <55107282+release-please[bot]@users.noreply.github.com>
Co-authored-by: Owl Bot <gcf-owl-bot[bot]@users.noreply.github.com>

Author: release-please[bot]

.release-please-manifest.json

@@ -779,7 +779,7 @@
   "google-cloud-spanner-admin-database-v1+FILLER": "0.0.0",
   "google-cloud-spanner-admin-instance-v1": "2.5.0",
   "google-cloud-spanner-admin-instance-v1+FILLER": "0.0.0",
-  "google-cloud-spanner-v1": "1.14.0",
+  "google-cloud-spanner-v1": "1.15.0",
   "google-cloud-spanner-v1+FILLER": "0.0.0",
   "google-cloud-speech": "2.0.4",
   "google-cloud-speech+FILLER": "0.0.0",

google-cloud-spanner-v1/CHANGELOG.md

@@ -1,5 +1,11 @@
 # Release History
 
+### 1.15.0 (2026-03-05)
+
+#### Features
+
+* include cache updates and routing hint into BeginTransaction and Commit request/response respectively ([#32790](https://github.com/googleapis/google-cloud-ruby/issues/32790)) 
+
 ### 1.14.0 (2026-02-18)
 
 #### Features

google-cloud-spanner-v1/lib/google/cloud/spanner/v1/version.rb

@@ -21,7 +21,7 @@ module Google
   module Cloud
     module Spanner
       module V1
-        VERSION = "1.14.0"
+        VERSION = "1.15.0"
       end
     end
   end

google-cloud-spanner-v1/snippets/snippet_metadata_google.spanner.v1.json

@@ -1,7 +1,7 @@
 {
   "client_library": {
     "name": "google-cloud-spanner-v1",
-    "version": "1.14.0",
+    "version": "1.15.0",
     "language": "RUBY",
     "apis": [
       {