For the universal parser, `rb_parser_reg_fragment_check` function is
shared between the parser and ripper.  However `parser_params` struct
is partially different, and `compile_error` function depends on that
part indirectly.

For the universal parser, `rb_reg_named_capture_assign_iter_impl`
function is shared between the parser and ripper.  However
`parser_params` struct is partially different, and `assignable`
function depends on that part indirectly.

The allocated parser string is never freed, which causes a memory leak.

The following code leaks memory:

    Ripper.sexp_raw(DATA.read)

    __END__
    <<~EOF
      a
        #{1}
      a
    EOF

This change is reduce Ruby C API dependency for Universal Parser.
Reuse dedent_string functions in rb_ruby_ripper_dedent_string functions and remove dependencies on rb_str_modify and rb_str_set_len from the parser.

This commit switches the default parser to Prism. There are a
couple of additional changes related to this that are a part of
this as well to make this happen.

* Switch the default parser in parse.h
* Remove the Prism-specific workflow and add a parse.y-specific
  workflow to CI so that it continues to be tested
* Update a few test exclusions since Prism has the correct
  behavior but parse.y doesn't per
  https://bugs.ruby-lang.org/issues/20504.
* Skips a couple of tests on RBS which are failing because they
  are using RubyVM::AbstractSyntaxTree.of.

Fixes [Feature #20564]

This way there is one place to change for switching the default.
This also allows for building the same commit with different cppflags.

Recently, `TestRubyLiteral#test_float` fails randomly.

```
  1) Error:
TestRubyLiteral#test_float:
ArgumentError: SyntaxError#path changed: "(eval at /home/chkbuild/chkbuild/tmp/build/20240527T050036Z/ruby/test/ruby/test_literal.rb:642)"->"(eval at /home/chkbuild/chkbuild/tmp/build/20240527T050036Z/ruby/test/ruby/test_literal.rb:642)"
```
https://rubyci.s3.amazonaws.com/s390x/ruby-master/log/20240527T050036Z.fail.html.gz

According to Launchable, the first failure was on Apr 30.
This is just when 528c4501f46fbe1e06028d673a777ef124d29829 was
committed. I don't know if the change is really the cause, but I want to
revert it once to see if the random failure disappears.

Fixed warning about discarding modifiers.

```
../src/ruby_parser.c:677:48: warning: passing 'rb_encoding *' (aka 'const struct OnigEncodingTypeST *') to parameter of type 'void *' discards qualifiers [-Wincompatible-pointer-types-discards-qualifiers]
  677 |     ast = rb_parser_compile(p, gets, ptr, len, enc, input, line);
      |                                                ^~~
../src/internal/parse.h:58:128: note: passing argument to parameter 'fname_enc' here
   58 | rb_ast_t *rb_parser_compile(rb_parser_t *p, rb_parser_lex_gets_func *gets, const char *fname_ptr, long fname_len, rb_encoding *fname_enc, rb_parser_input_data input, int line);
      |                                                                                                                                ^
```

This change reduces parser's dependency on ruby object.