Avoid directly calling version to avoid Sorbet error (#2663)

This will avoid breaking add-ons that don't define a `version` method and
doesn't require `ruby-lsp` as a dependency when displaying the add-ons in the UI.

lib/ruby_lsp/server.rb

@@ -89,7 +89,16 @@ def process_message(message)
             id: message[:id],
             response:
               Addon.addons.map do |addon|
-                { name: addon.name, version: addon.version, errored: addon.error? }
+                version_method = addon.method(:version)
+
+                # If the add-on doesn't define a `version` method, we'd be calling the abstract method defined by
+                # Sorbet, which would raise an error.
+                # Therefore, we only call the method if it's defined by the add-on itself
+                if version_method.owner != Addon
+                  version = addon.version
+                end
+
+                { name: addon.name, version: version, errored: addon.error? }
               end,
           ),
         )

test/server_test.rb

@@ -465,7 +465,8 @@ def test_workspace_addons
     refute(addons_info[0][:errored])
 
     assert_equal("Bar", addons_info[1][:name])
-    assert_equal("0.2.0", addons_info[1][:version])
+    # It doesn't define a `version` method
+    assert_nil(addons_info[1][:version])
     assert(addons_info[1][:errored])
   ensure
     RubyLsp::Addon.addons.clear
@@ -722,10 +723,6 @@ def name
       end
 
       def deactivate; end
-
-      def version
-        "0.2.0"
-      end
     end
   end