fix: Pin sqlite3 to 1.6 in appengine rails tests for compatibility with Ruby 2.7

Author: dazuma

appengine/rails-cloudsql-mysql/Gemfile

@@ -24,7 +24,9 @@ end
 gem "rails", "~> 7.0"
 
 # Use sqlite3 as the database for Active Record
-gem "sqlite3", "~> 1.6"
+# Pin to 1.6.x for compatibility with Ruby 2.7.
+# This can be relaxed when we drop support for Ruby 2.7.
+gem "sqlite3", "~> 1.6.6"
 # Use Puma as the app server
 gem "puma", "~> 6.3"
 # Use SCSS for stylesheets

appengine/rails-cloudsql-mysql/Gemfile.lock

@@ -335,7 +335,7 @@ DEPENDENCIES
   rspec-rails
   rspec_junit_formatter
   sass-rails (~> 6.0)
-  sqlite3 (~> 1.6)
+  sqlite3 (~> 1.6.6)
   tzinfo-data
   web-console (>= 4.2.0)