fix(init): read pyproject.toml as UTF-8

`get_default_version_provider` read pyproject.toml with the locale
encoding. TOML files are UTF-8, so on Windows a pyproject.toml with
non-ASCII text (for example an author name) made `cz init` fail with a
UnicodeDecodeError.

Assisted By: AI

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

Author: Alpenj

commitizen/project_info.py

@@ -27,7 +27,8 @@ def get_default_version_provider() -> Literal[
 ]:
     pyproject_path = Path("pyproject.toml")
     if pyproject_path.is_file():
-        if "[tool.poetry]" in pyproject_path.read_text():
+        # TOML files are UTF-8 by specification, whatever the locale encoding
+        if "[tool.poetry]" in pyproject_path.read_text(encoding="utf-8"):
             return "poetry"
         if Path("uv.lock").is_file():
             return "uv"

tests/test_project_info.py

@@ -15,7 +15,7 @@ def _create_project_files(files: dict[str, str | None]) -> None:
         if content is None:
             path.touch()
         else:
-            path.write_text(content)
+            path.write_text(content, encoding="utf-8")
 
 
 @pytest.mark.parametrize(
@@ -48,6 +48,11 @@ def test_available_hook_installers(mocker, which_map, expected):
             {"pyproject.toml": '[tool.poetry]\nname = "test"\nversion = "0.1.0"'},
             "poetry",
         ),
+        (
+            # Non-ASCII text that the cp949 and cp1252 code pages cannot decode
+            {"pyproject.toml": '[tool.poetry]\nname = "test"\nauthors = ["Łukasz ✨"]'},
+            "poetry",
+        ),
         ({"pyproject.toml": "", "uv.lock": ""}, "uv"),
         (
             {"pyproject.toml": '[tool.commitizen]\nversion = "0.1.0"'},