Finalize data migration and add FK on `Project#creator_id`

What does this MR do and why?

Related to #390641 (closed)

This MR

• Finalizes the data migration that we have already added in !110485 (merged), that was merged 2 weeks ago.
• After this data migration is finalized, a second post_deploy migration adds a foreign key relation on Project#creator_id to User#id, which is NOT VALID

Migrations

UP migration

$ rake db:migrate

main: == 20230223065753 FinalizeNullifyCreatorIdOfOrphanedProjects: migrating =======
main: == 20230223065753 FinalizeNullifyCreatorIdOfOrphanedProjects: migrated (0.0237s)

main: == 20230223093704 AddForeignKeyOnCreatorIdOnProjects: migrating ===============
main: -- transaction_open?()
main:    -> 0.0000s
main: -- transaction_open?()
main:    -> 0.0000s
main: -- execute("ALTER TABLE projects\nADD CONSTRAINT fk_03ec10b0d3\nFOREIGN KEY (creator_id)\nREFERENCES users (id)\n\nON DELETE SET NULL\nNOT VALID;\n")
main:    -> 0.0015s
main: == 20230223093704 AddForeignKeyOnCreatorIdOnProjects: migrated (0.0170s) ======

ci: == 20230223065753 FinalizeNullifyCreatorIdOfOrphanedProjects: migrating =======
ci: -- The migration is skipped since it modifies the schemas: [:gitlab_main].
ci: -- This database can only apply migrations in one of the following schemas: [:gitlab_ci, :gitlab_shared, :gitlab_internal].
ci: == 20230223065753 FinalizeNullifyCreatorIdOfOrphanedProjects: migrated (0.0064s)

ci: == 20230223093704 AddForeignKeyOnCreatorIdOnProjects: migrating ===============
ci: -- transaction_open?()
ci:    -> 0.0000s
ci: -- transaction_open?()
ci:    -> 0.0000s
ci: -- execute("ALTER TABLE projects\nADD CONSTRAINT fk_03ec10b0d3\nFOREIGN KEY (creator_id)\nREFERENCES users (id)\n\nON DELETE SET NULL\nNOT VALID;\n")
ci:    -> 0.0016s
ci: == 20230223093704 AddForeignKeyOnCreatorIdOnProjects: migrated (0.0152s) ======

DOWN Migrations

$ rake db:migrate:down:main VERSION=20230223093704

main: == 20230223093704 AddForeignKeyOnCreatorIdOnProjects: reverting ===============
main: -- transaction_open?()
main:    -> 0.0001s
main: -- remove_foreign_key(:projects, {:column=>:creator_id})
main:    -> 0.0071s
main: == 20230223093704 AddForeignKeyOnCreatorIdOnProjects: reverted (0.3172s) ======

$ rake db:migrate:down:ci VERSION=20230223093704

ci: == 20230223093704 AddForeignKeyOnCreatorIdOnProjects: reverting ===============
ci: -- transaction_open?()
ci:    -> 0.0000s
ci: -- remove_foreign_key(:projects, {:column=>:creator_id})
ci:    -> 0.0031s
ci: == 20230223093704 AddForeignKeyOnCreatorIdOnProjects: reverted (0.1310s) ======

$ rake db:migrate:down:main VERSION=20230223065753

main: == 20230223065753 FinalizeNullifyCreatorIdOfOrphanedProjects: reverting =======
main: == 20230223065753 FinalizeNullifyCreatorIdOfOrphanedProjects: reverted (0.0040s)

$ rake db:migrate:down:ci VERSION=20230223065753

ci: == 20230223065753 FinalizeNullifyCreatorIdOfOrphanedProjects: reverting =======
ci: -- The migration is skipped since it modifies the schemas: [:gitlab_main].
ci: -- This database can only apply migrations in one of the following schemas: [:gitlab_ci, :gitlab_shared, :gitlab_internal].
ci: == 20230223065753 FinalizeNullifyCreatorIdOfOrphanedProjects: reverted (0.0267s)

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MR acceptance checklist

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

Related to #390641 (closed)