ruby-ts-mode: Fine-tune s-p-f on symbols (bug#62086)

ruby-ts-mode: Fine-tune s-p-f on symbols (bug#62086)

* lisp/progmodes/ruby-ts-mode.el (ruby-ts--s-p-query):
Don't match ':' in symbol node text.  Or '_', I suppose.
(ruby-ts--syntax-propertize): Make sure to only put the '_' syntax
on punctuation syntax characters, and not on the whole symbol (to
e.g. have symbols like :foo? include text recognized as word).

* test/lisp/progmodes/ruby-ts-mode-tests.el
(ruby-ts-syntax-propertize-symbol): New test.