chore(main): release google-apis-core 1.2.1 (googleapis#26614)

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

Author: release-please[bot]

.release-please-manifest.json

@@ -1,5 +1,5 @@
 {
-  "google-apis-core": "1.2.0",
+  "google-apis-core": "1.2.1",
   "google-apis-core+FILLER": "0.0.0",
   "google-apis-generator": "0.19.0",
   "google-apis-generator+FILLER": "0.0.0"

google-apis-core/CHANGELOG.md

@@ -1,5 +1,11 @@
 # Release History
 
+### 1.2.1 (2026-06-09)
+
+#### Bug Fixes
+
+* Add missing multi_json runtime dependency for representable ([#26612](https://github.com/googleapis/google-api-ruby-client/issues/26612)) ([16afc11](https://github.com/googleapis/google-api-ruby-client/commit/16afc118f58d64a1394f33b76133d69ce4632575)), closes [#26611](https://github.com/googleapis/google-api-ruby-client/issues/26611) [#26613](https://github.com/googleapis/google-api-ruby-client/issues/26613)
+
 ### 1.2.0 (2026-06-04)
 
 #### Features

google-apis-core/lib/google/apis/core/version.rb

@@ -16,7 +16,7 @@ module Google
   module Apis
     module Core
       # Core version
-      VERSION = "1.2.0".freeze
+      VERSION = "1.2.1".freeze
     end
   end
 end