Update ROADMAP.md

[sumitmsft]

This pull request updates the ROADMAP.md file to reflect the current status and future plans for the Python Driver for SQL Server. Key changes include clarifications about the public preview status, updates to feature availability across platforms, and the addition of new planned features like Bulk Copy (BCP) support.

Updates to roadmap content:

• Updated introduction to specify that the Python Driver for SQL Server is now in Public Preview.
• Clarified that connection pooling is already available for Windows and will soon be extended to MacOS and Linux distributions.
• Revised cross-platform support details to focus on Linux distributions, with MacOS support no longer explicitly mentioned.

New feature announcements:

• Added Bulk Copy (BCP) API support to the roadmap, highlighting its use for high-speed data ingestion and large-scale ETL workflows.

Minor cleanup:

• Removed unnecessary blank lines at the end of the file for better formatting.

[Copilot]

Pull Request Overview

This PR updates the roadmap to reflect the current status and upcoming plans for the Python Driver for SQL Server, including clarifications on the public preview, connection pooling availability, adjusted cross-platform support, and newly announced Bulk Copy (BCP) support.

• Updated introduction to indicate public preview status.
• Modified connection pooling details and removed explicit MacOS support from cross-platform support.
• Added a new section introducing Bulk Copy (BCP) support.