Update factory_bot requirement from ~> 6.3.0 to ~> 6.4.6

Updates the requirements on [factory_bot](https://github.com/thoughtbot/factory_bot) to permit the latest version.
- [Release notes](https://github.com/thoughtbot/factory_bot/releases)
- [Changelog](https://github.com/thoughtbot/factory_bot/blob/main/NEWS.md)
- [Commits](thoughtbot/factory_bot@v6.3.0...v6.4.6)

---
updated-dependencies:
- dependency-name: factory_bot
  dependency-type: direct:production
...

Signed-off-by: dependabot[bot] <support@github.com>

Gemfile

@@ -3,7 +3,7 @@
 source "https://rubygems.org"
 gemspec
 
-gem "factory_bot", "~> 6.3.0"
+gem "factory_bot", "~> 6.4.6"
 gem "minitest", "~> 5.11"
 gem "minitest-snapshots", "~> 1.1"
 gem "mocha", "~> 2.4"