Background:
Podman now uses SQLite as its default database for storing container and metadata information. However, some users may still be running with BoltDB from previous installations. BoltDB support will be fully removed in Podman 6.0, so these users need to be informed about the deprecation and encouraged to migrate to SQLite.

Description:
Add deprecation warnings for users who are still using BoltDB to inform them that BoltDB support will be removed in Podman 6.0 and they should migrate to SQLite (which is already the default).

Completion Criteria:
1. Detection & Warning Logic:

• Detect when BoltDB is being used as the active database backend
• Emit clear deprecation warnings during Podman operations
• Include warnings in appropriate log levels

2. User Communication:

• Provide clear warning messages about BoltDB deprecation
• Specify that BoltDB will be removed in Podman 6.0
• Include guidance on how to migrate from BoltDB to SQLite

3. Documentation Updates:

• Document the deprecation notice in release notes
• Update migration documentation with BoltDB to SQLite steps
• Include troubleshooting information for migration issues

4. Testing:

• Verify warnings appear when BoltDB is detected
• Test that warnings don't appear when SQLite is in use
• Ensure migration guidance is accurate