Fix test_syntax not to use identity comparison on string

Fix test_syntax to compare strings via "==" rather than "is", in order
to fix test failure on PyPy3.

CHANGELOG.md

@@ -11,6 +11,10 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 - Add support for US spelling of "gray" in ANSI color names https://github.com/Textualize/rich/issues/1890
 
+### Fixed
+
+- Fixed `test_syntax.py::test_from_path_lexer_override` test failure on PyPy3 https://github.com/Textualize/rich/pull/1904
+
 ## [11.1.0] - 2022-01-28
 
 ### Added

CONTRIBUTORS.md

@@ -27,3 +27,4 @@ The following people have contributed to the development of Rich:
 - [Nicolas Simonds](https://github.com/0xDEC0DE)
 - [Gabriele N. Tornetta](https://github.com/p403n1x87)
 - [Patrick Arminio](https://github.com/patrick91)
+- [Michał Górny](https://github.com/mgorny)

tests/test_syntax.py

@@ -277,7 +277,7 @@ def test_from_path_lexer_override():
     try:
         os.write(fh, b"import this\n")
         syntax = Syntax.from_path(path, lexer="rust")
-        assert syntax.lexer.name is "Rust"
+        assert syntax.lexer.name == "Rust"
         assert syntax.code == "import this\n"
     finally:
         os.remove(path)