fs/extension handles paths with dot incorrectly

[dbohdan]

> bb -e '(fs/extension "/foo/example.com/data")'
"com/data"
> bb --version
babashka v1.0.167

[dbohdan]

The current fix is IMO wrong. It changes split-ext from a pure function that operates on abstract paths to one whose result depends on the state of your filesystem, which is undesirable. It doesn't help you with remote or abstract paths. Instead, it would be better if it just made sure the last . in the path was after the last /.

[borkdude]

@dbohdan I agree with that, I misunderstood the original issue

[borkdude]

Done