Fix failure of more command with -R option

[hogelog]

I believe the more command generally does not accept the raw option (-R).
As an example, the more command man included in util-linux shown below does not have the -R option.
https://man7.org/linux/man-pages/man1/more.1.html
When I run pager with irb in an environment where the -less command does not exist, I get the following error

root@12afc3afe8da:/app# irb
irb(main):001> ls File
more: invalid option -- 'R'
Try 'more --help' for more information.
=> nil
irb(main):002> 

After installing the irb gem with this Pulll Request modification, I was able to successfully execute pagenation with more.

[hogelog]

The test is failing. Seems like perhaps a fix in @tompng's https://github.com/tompng/irb/tree/prism_match_write_case_match branch would fix it.

[hogelog]

Rebased onto 943c14b and force pushed to pass test.

[tompng]

Thank you for the pull request.

In my macOS, more command accepted -R option because it was actually less (!)

$ more --version
less 581.2 (POSIX regular expressions)
Copyright (C) 1984-2021  Mark Nudelman

less comes with NO WARRANTY, to the extent permitted by law.
For information about the terms of redistribution,
see the file named README in the less distribution.
Home page: https://greenwoodsoftware.com/less

[hogelog]

Thank you for merging this!

In my macOS, more command accepted -R option because it was actually less (!)

Yes, exactly what I was confused about at first too😅