Update dependency paper_trail to v15

[renovate]

This PR contains the following updates:

Package	Update	Change
paper_trail (source)	major	'~> 14.0' -> '~> 15.0'

---

Release Notes

airblade/paper_trail (paper_trail)

v15.0.0

Compare Source

Breaking Changes

• None

Added

• #​1416 - Adds a
  model-configurable option synchronize_version_creation_timestamp which, if
  set to false, opts out of synchronizing timestamps between Version.created_at
  and the record's updated_at.

Fixed

• #​1422 - Fix the
  issue that unencrypted plaintext values are versioned with ActiveRecord
  encryption (since Rails 7) when using JSON serialization on PostgreSQL json
  columns.
• #​1414 - When
  generating the migration, the version table will use uuid as primary key type
  if --uuid flag is specified.

Dependencies

• Drop support for Rails 6.0, which [reached EoL on 2023-06-01][2]
• Drop support for Ruby 2.7, which [reached EoL on 2023-03-31][3]

---

Configuration

📅 Schedule: Branch creation - At any time (no schedule defined), Automerge - At any time (no schedule defined).

🚦 Automerge: Disabled by config. Please merge this manually once you are satisfied.

♻ Rebasing: Whenever PR becomes conflicted, or you tick the rebase/retry checkbox.

🔕 Ignore: Close this PR and you won't be reminded about this update again.

---

• If you want to rebase/retry this PR, check this box

---

This PR has been generated by Mend Renovate. View repository job log here.