chore(specs): drop redundant type metadata

[ankuanku1]

Closes #2934

infer_spec_type_from_file_location! doesn't cover spec/services, spec/presenters or spec/lib/tasks, so not all of the type: metadata in these specs was redundant. Removing type: :task breaks the rake specs, because TaskExampleGroup (which defines task) is only included for that type. spec/support/rake_tasks.rb was meant to add the tag automatically, but it matched %r{/spec/tasks/}, a folder that didn't exist. This changes it to %r{/spec/lib/tasks/} and drops the type: from all 12 specs listed in the issue.

RuboCop's RSpec/DescribeClass only allows a string describe when it can see a type like type: :task in the file, and it can't see tags that RSpec assigns from the path. So spec/lib/tasks/**/* is now excluded from that cop in .rubocop.yml. workshop_presenter_capacity_spec.rb was a string tagged type: :model. It now uses describe WorkshopPresenter and described_class, the same as workshop_presenter_spec.rb. Nothing uses :service, so the service specs behave the same.

Testing

• bundle exec parallel_rspec spec/ -n 3: 1552 examples, 0 failures
• bundle exec rspec spec/lib/tasks --dry-run --tag type:task: all 18 rake examples selected (the tag now comes from the path)
• bundle exec rubocop: no offenses

[mroderick]

Reviewed and verified in a worktree of the PR branch:

• The root cause is real: spec/support/rake_tasks.rb tagged files via %r{/spec/tasks/}, a directory that doesn't exist; the rake specs live in spec/lib/tasks/ and only got type: :task from their explicit per-file tags. The fix points the derived metadata at the real path, and config.include TaskExampleGroup, type: :task is the only type: consumer in the support stack.
• The other tag removals are safe: infer_spec_type_from_file_location! has no mappings for spec/services, spec/presenters, or spec/lib/tasks, and nothing includes an example group for :service. All 12 files listed in #2934 match the changed spec files.
• workshop_presenter_capacity_spec.rb now matches its sibling workshop_presenter_spec.rb (class describe + described_class), which was already written that way.
• The RSpec/DescribeClass exclusion is scoped to spec/lib/tasks/**/* only.
• Ran from the worktree: full parallel_rspec spec/ -n 3 — 1552 examples, 0 failures; rspec spec/lib/tasks --dry-run --tag type:task — all 18 rake examples selected via the path-derived tag; full rubocop — 436 files, no offenses.