build: update gemspec version to require version 7.0 or higher (#354)

Author: olavloite

acceptance/cases/tasks/database_tasks_test.rb

@@ -75,13 +75,9 @@ def test_structure_dump_and_load
         create_tables_in_test_schema
 
         db_config =
-          if ActiveRecord.version >= Gem::Version.new("6.1")
-            ActiveRecord::DatabaseConfigurations::HashConfig.new "test",
-                                                                 "primary",
-                                                                 connector_config
-          else
-            connector_config
-          end
+          ActiveRecord::DatabaseConfigurations::HashConfig.new "test",
+                                                               "primary",
+                                                               connector_config
 
         tables = connection.tables.sort
         config_name = "primary"

activerecord-spanner-adapter.gemspec

@@ -27,7 +27,7 @@ Gem::Specification.new do |spec|
   spec.add_dependency "google-cloud-spanner", "~> 2.18"
   # Pin gRPC to 1.64.3, as 1.65 and 1.66 cause test runs to hang randomly.
   spec.add_dependency "grpc", "1.64.3"
-  spec.add_runtime_dependency "activerecord", [">= 6.1", "< 9"]
+  spec.add_runtime_dependency "activerecord", [">= 7.0", "< 9"]
 
   spec.add_development_dependency "autotest-suffix", "~> 1.1"
   spec.add_development_dependency "bundler", "~> 2.0"

lib/active_record/connection_adapters/spanner/schema_statements.rb

@@ -21,8 +21,6 @@ module Spanner
       # [Schema Doc](https://cloud.google.com/spanner/docs/information-schema)
       #
       module SchemaStatements
-        VERSION_6_1_0 = Gem::Version.create "6.1.0"
-        VERSION_6_0_3 = Gem::Version.create "6.0.3"
         VERSION_7_2 = Gem::Version.create "7.2.0"
 
         def current_database