chore: bump version to 1.2.0 (#170)

Co-authored-by: datacommons-robot-author <datacommons-robot-author@users.noreply.github.com>

Author: datacommons-robot-author

packages/datacommons-mcp/pyproject.toml

@@ -1,6 +1,6 @@
 [project]
 name = "datacommons-mcp"
-version = "1.1.7"
+version = "1.2.0"
 description = "Data Commons MCP server."
 readme = "README.md"
 requires-python = ">=3.11, <3.14"