Improve read_pyproject docstring with reStructuredText format

Convert docstring to reStructuredText format and document both test hooks
(_given_result and _given_definition). Clarifies that _given_definition is
ignored when _given_result is provided.

Note: Python 3.10 pin removed from pre-commit configuration.

🤖 Generated with [Claude Code](https://claude.com/claude-code)

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

Author: RonnyPfannschmidt

.pre-commit-config.yaml

@@ -18,7 +18,6 @@ repos:
     hooks:
     -   id: mypy
         args: [--strict]
-        language_version: "3.10"
         additional_dependencies:
             - types-setuptools
             - tokenize-rt==3.2.0

src/setuptools_scm/_integration/pyproject_reading.py

@@ -178,16 +178,19 @@ def read_pyproject(
 ) -> PyProjectData:
     """Read and parse pyproject configuration.
 
-    This function supports dependency injection for tests via `_given_result`.
-
-    Parameters:
-    - path: Path to the pyproject file
-    - tool_name: The tool section name (default: `setuptools_scm`)
-    - canonical_build_package_name: Normalized build requirement name
-    - _given_result: Optional testing hook. Can be:
-        - PyProjectData: returned directly
-        - InvalidTomlError | FileNotFoundError: raised directly
-        - None: read from filesystem
+    This function supports dependency injection for tests via ``_given_result``
+    and ``_given_definition``.
+
+    :param path: Path to the pyproject file
+    :param tool_name: The tool section name (default: ``setuptools_scm``)
+    :param canonical_build_package_name: Normalized build requirement name
+    :param _given_result: Optional testing hook. Can be:
+        - ``PyProjectData``: returned directly
+        - ``InvalidTomlError`` | ``FileNotFoundError``: raised directly
+        - ``None``: read from filesystem (default)
+    :param _given_definition: Optional testing hook to provide parsed TOML content.
+        When provided, this dictionary is used instead of reading and parsing
+        the file from disk. Ignored if ``_given_result`` is provided.
     """
 
     if _given_result is not None: