chore: revert bigtable-admin to Gapic V1 for Ruby only

PiperOrigin-RevId: 307114445

google/bigtable/admin/artman_bigtableadmin.legacy.yaml

@@ -0,0 +1,19 @@
+common:
+  api_name: bigtable-admin
+  api_version: v2
+  organization_name: google-cloud
+  service_yaml: v2/bigtableadmin_v2.yaml
+  gapic_yaml: v2/bigtableadmin_gapic.legacy.yaml
+  src_proto_paths:
+  - v2
+  proto_deps:
+  - name: google-common-protos
+  - name: google-iam-v1
+    proto_path: google/iam/v1
+  test_proto_deps:
+  - name: google-iam-v1
+    proto_path: google/iam/v1
+artifacts:
+- name: ruby_gapic
+  type: GAPIC
+  language: RUBY

google/bigtable/admin/artman_bigtableadmin.yaml

@@ -23,9 +23,6 @@ artifacts:
 - name: php_gapic
   type: GAPIC
   language: PHP
-- name: ruby_gapic
-  type: GAPIC
-  language: RUBY
 - name: go_gapic
   type: GAPIC
   language: GO