Update entr from 2.2 to 2.6. Notable features:

* Reduce number of attempts to re-open files to 1 second (10 attempts)
* Wait for processes to terminate in restart mode
* Prevent interactive utilities from paging output by setting PAGER to `/bin/cat`
* First match of `/_` provides a shortcut for specifying the first file under watch
* New `-c` option invokes `clear` before running the utility
* Support Vim's `backup` option by responding to `NOTE_RENAME`