Don't attach LSP to syntax test files (#2531)

Co-authored-by: Rafał Chłodnicki <[email protected]>

plugin/documents.py

@@ -56,6 +56,7 @@
 from .session_view import SessionView
 from functools import partial
 from functools import wraps
+from os.path import basename
 from typing import Any, Callable, Generator, Iterable, TypeVar
 from typing import cast
 from typing_extensions import Concatenate, ParamSpec
@@ -95,6 +96,10 @@ def is_regular_view(v: sublime.View) -> bool:
         return False
     if v.settings().get('is_widget'):
         return False
+    # Not a syntax test file.
+    if (filename := v.file_name()) and basename(filename).startswith('syntax_test_'):
+        return False
+    # Not a transient sheet (preview).
     sheet = v.sheet()
     if not sheet:
         return False