Fix "Publish to PyPI" workflow: Add commit signing and improve diff (#82)

* Adds commit signing
* Converts sed pattern matching to a script to ensure we don't update
version values unrelated to PyPI
* Remove the `Publish to Test PyPI first'` step since it no longer works

scripts/update_version.py

@@ -0,0 +1,49 @@
+#!/usr/bin/env python3
+"""Update version in pyproject.toml and __init__.py files."""
+
+import sys
+import re
+from pathlib import Path
+
+
+def update_version(new_version: str) -> None:
+    """Update version in project files."""
+    # Update pyproject.toml
+    pyproject_path = Path("pyproject.toml")
+    content = pyproject_path.read_text()
+    
+    # Only update the version field in [project] section
+    content = re.sub(
+        r'^version = "[^"]*"',
+        f'version = "{new_version}"',
+        content,
+        count=1,
+        flags=re.MULTILINE
+    )
+    
+    pyproject_path.write_text(content)
+    print(f"Updated pyproject.toml to version {new_version}")
+    
+    # Update __init__.py
+    init_path = Path("src/claude_code_sdk/__init__.py")
+    content = init_path.read_text()
+    
+    # Only update __version__ assignment
+    content = re.sub(
+        r'^__version__ = "[^"]*"',
+        f'__version__ = "{new_version}"',
+        content,
+        count=1,
+        flags=re.MULTILINE
+    )
+    
+    init_path.write_text(content)
+    print(f"Updated __init__.py to version {new_version}")
+
+
+if __name__ == "__main__":
+    if len(sys.argv) != 2:
+        print("Usage: python scripts/update_version.py <version>")
+        sys.exit(1)
+    
+    update_version(sys.argv[1])