Replace default_value_for with Rails attributes API

The current version of default_value_for does not support Rails 7 and it looks almost unmaintained: https://github.com/FooBarWidget/default_value_for/issues/92

In Rails 6 we can use the attributes API to set default values:

diff --git a/app/models/commit_status.rb b/app/models/commit_status.rb
index 05a258e6e26..ae16cb1edf3 100644
--- a/app/models/commit_status.rb
+++ b/app/models/commit_status.rb
@@ -102,7 +102,7 @@ class CommitStatus < Ci::ApplicationRecord
   # extend this `Hash` with new values.
   enum_with_nil failure_reason: Enums::Ci::CommitStatus.failure_reasons
 
-  default_value_for :retried, false
+  attribute :retried, default: false
 
   ##
   # We still create some CommitStatuses outside of CreatePipelineService.
diff --git a/app/models/deploy_token.rb b/app/models/deploy_token.rb
index 20d19ec9541..39baf159c15 100644
--- a/app/models/deploy_token.rb
+++ b/app/models/deploy_token.rb
@@ -13,7 +13,7 @@ class DeployToken < ApplicationRecord
   GITLAB_DEPLOY_TOKEN_NAME = 'gitlab-deploy-token'
   REQUIRED_DEPENDENCY_PROXY_SCOPES = %i[read_registry write_registry].freeze
 
-  default_value_for(:expires_at) { Forever.date }
+  attribute :expires_at, default: -> { Forever.date }
 
   # Do NOT use this `user` for the authentication/authorization of the deploy tokens.
   # It's for the auditing purpose on Credential Inventory, only.

Previous discussion: &7875 (comment 1131452313)

Models that use this gem:

• AlertManagement::HttpIntegration
• Appearance
• ApplicationSetting
• ApprovalProjectRule
• BroadcastMessage
• Ci::Build
• Ci::BuildTraceChunk
• Ci::SecureFile
• Clusters::Applications::CertManager
• Clusters::Applications::Crossplane
• Clusters::Applications::Helm
• Clusters::Applications::Ingress
• Clusters::Applications::Jupyter
• Clusters::Applications::Knative
• Clusters::Applications::Prometheus
• Clusters::Applications::Runner
• Clusters::Cluster
• Clusters::Integrations::Prometheus
• Clusters::Platforms::Kubernetes
• Clusters::Providers::Aws
• Clusters::Providers::Gcp
• CommitStatus
• DependencyProxy::Blob
• DependencyProxy::GroupSetting
• DependencyProxy::Manifest
• DeployToken
• Epic
• GitlabSubscription
• Groups::FeatureSetting
• Groups::RepositoryStorageMove
• Integration
• Issue
• Label
• Member
• MergeRequest
• Ml::Candidate
• Note
• NotificationSetting
• Operations::FeatureFlag
• PagesDomain
• Project
• ProjectCiCdSetting
• ProjectFeature
• ProjectSetting
• ProjectStatistics
• Projects::RepositoryStorageMove
• Serverless::DomainCluster
• Snippets::RepositoryStorageMove
• Terraform::State
• Terraform::StateVersion
• TimeTracking::TimelogCategory
• User
• UserPreference

You can use _default: :mystring for enum and after_initialize if: :new_record? for attr_encrypted attribute.

ApplicationRecord.descendants.reject(&:abstract_class?).select {|klass| klass.try(:_default_attribute_values?) && !(!klass.superclass.abstract_class? && klass._default_attributes.keys == klass.superclass._default_attributes.keys)}.map(&:name).sort.map { |model| " - [ ] `#{model}`" }.join("\n")