Remove some explicit dependencies from the gemfile

* matrix: teamcapybara/capybara#2468
* `nokogiri 🤷 but there's no version constraint anyways
* `net-*`: mikel/mail#1472

It's been quite a while so these seem safe to drop

Gemfile

@@ -21,8 +21,6 @@ gemspec
 
 gem 'activerecord-jdbcpostgresql-adapter', platforms: [:jruby]
 gem 'appraisal'
-gem 'matrix'
-gem 'nokogiri'
 gem 'pg', platforms: [:mri, :mingw, :x64_mingw]
 gem 'rack', '~> 2.2'
 gem 'rails'
@@ -33,9 +31,6 @@ platforms :ruby do
   gem "foreman"
   gem "gem-release"
   gem "github_changelog_generator", require: false
-  gem "net-imap", require: false
-  gem "net-pop", require: false
-  gem "net-smtp", require: false
 
   group :debug do
     gem "activerecord-explain-analyze", require: false

Gemfile.lock

@@ -521,13 +521,8 @@ DEPENDENCIES
   i18n-tasks
   kramdown
   kramdown-parser-gfm
-  matrix
   mdl
   memory_profiler
-  net-imap
-  net-pop
-  net-smtp
-  nokogiri
   pg
   puma
   rack (~> 2.2)

gemfiles/rails_6.1.gemfile

@@ -4,8 +4,6 @@ source "https://rubygems.org"
 
 gem "activerecord-jdbcpostgresql-adapter", platforms: [:jruby]
 gem "appraisal"
-gem "matrix"
-gem "nokogiri"
 gem "pg", platforms: [:mri, :mingw, :x64_mingw]
 gem "rack", "~> 2.2"
 gem "rails", "~> 6.1.0"
@@ -18,9 +16,6 @@ platforms :ruby do
   gem "foreman"
   gem "gem-release"
   gem "github_changelog_generator", require: false
-  gem "net-imap", require: false
-  gem "net-pop", require: false
-  gem "net-smtp", require: false
 
   group :debug do
     gem "activerecord-explain-analyze", require: false

gemfiles/rails_7.0_ruby_3.1.gemfile

@@ -4,8 +4,6 @@ source "https://rubygems.org"
 
 gem "activerecord-jdbcpostgresql-adapter", platforms: [:jruby]
 gem "appraisal"
-gem "matrix"
-gem "nokogiri"
 gem "pg", platforms: [:mri, :mingw, :x64_mingw]
 gem "rack", "~> 2.2"
 gem "rails", "~> 7.0.1"
@@ -16,9 +14,6 @@ platforms :ruby do
   gem "foreman"
   gem "gem-release"
   gem "github_changelog_generator", require: false
-  gem "net-imap", require: false
-  gem "net-pop", require: false
-  gem "net-smtp", require: false
 
   group :debug do
     gem "activerecord-explain-analyze", require: false

gemfiles/rails_7.1_ruby_3.1.gemfile

@@ -4,8 +4,6 @@ source "https://rubygems.org"
 
 gem "activerecord-jdbcpostgresql-adapter", platforms: [:jruby]
 gem "appraisal"
-gem "matrix"
-gem "nokogiri"
 gem "pg", platforms: [:mri, :mingw, :x64_mingw]
 gem "rack", "~> 2.2"
 gem "rails", "~> 7.1.0"
@@ -16,9 +14,6 @@ platforms :ruby do
   gem "foreman"
   gem "gem-release"
   gem "github_changelog_generator", require: false
-  gem "net-imap", require: false
-  gem "net-pop", require: false
-  gem "net-smtp", require: false
 
   group :debug do
     gem "activerecord-explain-analyze", require: false

gemfiles/rails_7.2_ruby_3.1.gemfile

@@ -4,8 +4,6 @@ source "https://rubygems.org"
 
 gem "activerecord-jdbcpostgresql-adapter", platforms: [:jruby]
 gem "appraisal"
-gem "matrix"
-gem "nokogiri"
 gem "pg", platforms: [:mri, :mingw, :x64_mingw]
 gem "rack", "~> 2.2"
 gem "rails", "~> 7.2.0"
@@ -16,9 +14,6 @@ platforms :ruby do
   gem "foreman"
   gem "gem-release"
   gem "github_changelog_generator", require: false
-  gem "net-imap", require: false
-  gem "net-pop", require: false
-  gem "net-smtp", require: false
 
   group :debug do
     gem "activerecord-explain-analyze", require: false

gemfiles/rails_8.0_ruby_3.2.gemfile

@@ -4,8 +4,6 @@ source "https://rubygems.org"
 
 gem "activerecord-jdbcpostgresql-adapter", platforms: [:jruby]
 gem "appraisal"
-gem "matrix"
-gem "nokogiri"
 gem "pg", platforms: [:mri, :mingw, :x64_mingw]
 gem "rack", "~> 2.2"
 gem "rails", "~> 8.0.0.a"
@@ -16,9 +14,6 @@ platforms :ruby do
   gem "foreman"
   gem "gem-release"
   gem "github_changelog_generator", require: false
-  gem "net-imap", require: false
-  gem "net-pop", require: false
-  gem "net-smtp", require: false
 
   group :debug do
     gem "activerecord-explain-analyze", require: false

gemfiles/rails_head.gemfile

@@ -4,8 +4,6 @@ source "https://rubygems.org"
 
 gem "activerecord-jdbcpostgresql-adapter", platforms: [:jruby]
 gem "appraisal"
-gem "matrix"
-gem "nokogiri"
 gem "pg", platforms: [:mri, :mingw, :x64_mingw]
 gem "rack", "~> 2.2"
 gem "rails", branch: "main", git: "https://github.com/rails/rails.git"
@@ -16,9 +14,6 @@ platforms :ruby do
   gem "foreman"
   gem "gem-release"
   gem "github_changelog_generator", require: false
-  gem "net-imap", require: false
-  gem "net-pop", require: false
-  gem "net-smtp", require: false
 
   group :debug do
     gem "activerecord-explain-analyze", require: false