script_binding: Add type check on servo script bindings (#38161)

Introduce type checking with Pyrefly in `components/script_bindings`

This commit adds Pyrefly-based type checking to the
`components/script_bindings` directory. The primary goal is to catch
type inconsistencies early and reduce the likelihood of unexpected
runtime errors.

This change affects the `webidl` component, as these script bindings are
responsible for connecting WebIDL specifications to the Rust codebase.

Testing: `./mach test-wpt webidl`
Fixes: *Link to an issue this pull requests fixes or remove this line if
there is no issue*

---------

Signed-off-by: Jerens Lensun <jerensslensun@gmail.com>

third_party/WebIDL/WebIDL.py

@@ -12,6 +12,7 @@ import string
 import traceback
 from collections import OrderedDict, defaultdict
 from itertools import chain
+from typing import Any
 
 from ply import lex, yacc
 
@@ -2522,7 +2523,7 @@ class IDLEnum(IDLObjectWithIdentifier):
 
 
 class IDLType(IDLObject):
-    Tags = enum(
+    Tags: Any = enum(
         # The integer types
         "int8",
         "uint8",

third_party/WebIDL/idltype-tags-type-hint.patch

@@ -0,0 +1,21 @@
+diff --git a/third_party/WebIDL/WebIDL.py b/third_party/WebIDL/WebIDL.py
+index b742a06bddd..babad83322f 100644
+--- a/third_party/WebIDL/WebIDL.py
++++ b/third_party/WebIDL/WebIDL.py
+@@ -12,6 +12,7 @@ import string
+ import traceback
+ from collections import OrderedDict, defaultdict
+ from itertools import chain
++from typing import Any
+ 
+ from ply import lex, yacc
+ 
+@@ -2527,7 +2528,7 @@ class IDLEnum(IDLObjectWithIdentifier):
+ 
+ 
+ class IDLType(IDLObject):
+-    Tags = enum(
++    Tags: Any = enum(
+         # The integer types
+         "int8",
+         "uint8",

third_party/WebIDL/update.sh

@@ -8,6 +8,7 @@ patch < like-as-iterable.patch
 patch < builtin-array.patch
 patch < array-type.patch
 patch < transferable.patch
+patch < idltype-tags-type-hint.patch
 
 wget https://hg.mozilla.org/mozilla-central/archive/tip.zip/dom/bindings/parser/tests/ -O tests.zip
 rm -r tests