Bump version to 2.6.3 across all projects

[masesdevelopers]

Description

Updated version numbers from 2.6.2 to 2.6.3 in Maven, NuGet, PowerShell module, and .NET project files to prepare for a new release.

Related Issue

fix #53

Motivation and Context

How Has This Been Tested?

Screenshots (if appropriate):

Types of changes

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to change)

Checklist:

• My code follows the code style of this project.
• My change requires a change to the documentation.
• I have updated the documentation accordingly.
• I have read the CONTRIBUTING document.
• I have added tests to cover my changes.
• All new and existing tests passed.