chore(nvim): update Command-T submodule

* aspects/nvim/files/.config/nvim/pack/bundle/opt/command-t 9a4cbf9...1fbbeb6 (21):
  > fix(lua): correct FFI problem on ARM64
  > fix(lua): stop dirvish from causing text to go invisible
  > fix(lua): fix a bad existence check
  > fix(lua): stop items from opening in splits
  > fix(lua): add missing items to `allowed_options`
  > feat(lua): implement 'smartcase' functionality
  > refactor(lua): rename `case_sensitive` to `ignore_case`
  > fix(lua): restore current window before running open command
  > fix(lua): suppress unwanted search highlighting in UI
  > fix(lua): don't try to open nothing
  > feat(lua): teach Watchman layer to degrade gracefully
  > chore(lua): add a code comment about another possible watchman error
  > fix(lua): bail as soon as user enters command mode
  > refactor(lua): tweak an error message
  > feat(lua): add `commandt.default_options()`
  > refactor(lua): remove dead, buggy code
  > fix(lua): avoid error when match listing has no matches
  > feat(lua): add more movement bindings
  > feat(lua): add check for working C library to `setup()`
  > chore: remove vendor/vimscriptuploader
  > chore: remove vendor/vroom