Fix error when parsing ERB files with yield on the top level

Top level yields are invalid Ruby on files, but are valid on `eval`.

They exist on ERB files, and since those files are evaluated no written
to disk they are fine.

We can tell Prism to parse the code using the eval context by passing
`scopes: [[]]` to `parse`, but since are are using the
`Prism::Translation::Parser` class we have no way to do that.

A [PR][1] was proposed to Prism to always consider the code as being
evaluated in the `Parser` translation.

For now, we can safely ignore that class of error by overriding the
`valid_error?` method on our own parser.

Fixes #400.

[1]: ruby/prism#2741

Gemfile.lock

@@ -9,7 +9,7 @@ PATH
       constant_resolver (>= 0.2.0)
       parallel
       parser
-      prism (>= 0.24.0)
+      prism (>= 0.25.0)
       sorbet-runtime (>= 0.5.9914)
       zeitwerk (>= 2.6.1)
 
@@ -77,7 +77,7 @@ GEM
       ast (~> 2.4.1)
       racc
     prettier_print (0.1.0)
-    prism (0.24.0)
+    prism (0.27.0)
     racc (1.7.1)
     rack (2.2.4)
     rack-test (2.0.2)

lib/packwerk/parsers/ruby.rb

@@ -19,6 +19,13 @@ def initialize(builder)
           super(builder)
           super.diagnostics.all_errors_are_fatal = true
         end
+
+        private
+
+        sig { params(error: Prism::ParseError).returns(T::Boolean) }
+        def valid_error?(error)
+          error.type != :invalid_yield
+        end
       end
 
       class TolerateInvalidUtf8Builder < Parser::Builders::Default

packwerk.gemspec

@@ -48,7 +48,7 @@ Gem::Specification.new do |spec|
   # For Ruby parsing
   spec.add_dependency("ast")
   spec.add_dependency("parser")
-  spec.add_dependency("prism", ">= 0.24.0") # 0.24.0 fixes a performance issue with the parser translator
+  spec.add_dependency("prism", ">= 0.25.0")
 
   # For ERB parsing
   spec.add_dependency("better_html")