rbenv: dynamically extend $PATH for gem binaries

I got rbenv installed, and it works fine:

$ rbenv local
3.2.0
$ ruby --version
ruby 3.2.0 (2022-12-25 revision a528908271) [x86_64-linux]

I installed the gem rufo to format my code, which worked fine:

$ gem install rufo

It seems that rbenv is aware of the binary location of rufo:

$ rbenv which rufo
/home/patrick/.rbenv/versions/3.2.0/bin/rufo

However, it cannot be found in my $PATH:

$ which rufo
which: no rufo in (…)

I can run it as follows to format my file hello.rb:

$ `rbenv which rufo` hello.rb
$ echo $?
0

However, I'd like to call it directly as follows:

$ rufo hello.rb

What do I need to configure?

Run rbenv rehash to update the shims:

$ which rufo 
which: no rufo in (…)

$ rbenv rehash
$ which rufo
/home/patrick/.rbenv/shims/rufo