Add version bump script for manifest synchronization

[rohan-pandeyy]

Description

PictoPy currently stores version information in multiple manifest files, which can lead to version drift during releases. The repository already contains an example where different manifests have different version numbers.

Proposed Solution

Add a version bump script (scripts/bump-version.mjs) that serves as the standard way to update application versions.

The script should:

• Accept a version number as input.
• Update all version declarations across the project's manifests.
• Ensure all version files remain synchronized after a release bump.

Benefits

• Prevents version drift between manifests.
• Simplifies the release process.
• Provides a single workflow for updating application versions.

Acceptance Criteria

• scripts/bump-version.mjs is added.
• The script updates all relevant manifest files.
• Maintainers/Contributors can bump versions using a single command.
• Version values remain synchronized across the project.