Remove deprecated package application setting

🔬 What does this MR do and why?

Removes an application setting column max_package_files_for_package_destruction that is no longer used after 14.7. This is step 2 in the dropping columns process.

💾 Database

Migration output

🛫 Up:

== 20220216201949 RemovePackageFilesLimitFromApplicationSettings: migrating ===
-- column_exists?(:application_settings, :max_package_files_for_package_destruction)
   -> 0.1774s
-- remove_column(:application_settings, :max_package_files_for_package_destruction, :smallint)
   -> 0.0070s
== 20220216201949 RemovePackageFilesLimitFromApplicationSettings: migrated (0.1847s)

🛬 Down:

== 20220216201949 RemovePackageFilesLimitFromApplicationSettings: reverting ===
-- add_column(:application_settings, :max_package_files_for_package_destruction, :smallint, {:default=>100, :null=>false})
   -> 0.0086s
-- transaction_open?()
   -> 0.0000s
-- current_schema()
   -> 0.0003s
-- transaction_open?()
   -> 0.0000s
-- execute("ALTER TABLE application_settings\nADD CONSTRAINT app_settings_max_package_files_for_package_destruction_positive\nCHECK ( max_package_files_for_package_destruction > 0 )\nNOT VALID;\n")
   -> 0.0027s
-- current_schema()
   -> 0.0003s
-- execute("SET statement_timeout TO 0")
   -> 0.0008s
-- execute("ALTER TABLE application_settings VALIDATE CONSTRAINT app_settings_max_package_files_for_package_destruction_positive;")
   -> 0.0022s
-- execute("RESET statement_timeout")
   -> 0.0008s
== 20220216201949 RemovePackageFilesLimitFromApplicationSettings: reverted (0.0376s)

Screenshots or screen recordings

N/A

💻 How to set up and validate locally

The migrations can be run locally via bundle exec rails db:migrate

📝 MR acceptance checklist

This checklist encourages us to confirm any changes have been analyzed to reduce risks in quality, performance, reliability, security, and maintainability.

• I have evaluated the MR acceptance checklist for this MR.

Related to #351296 (closed)