Update Node.js to version 22

[niinaad5]

What does this PR do?

Updates the repository to use Node.js 22 instead of the unsupported Node.js 18 version.

Changes

• Updated Node.js to 22 in the CI workflow
• Updated Node.js to 22 in the translation update workflow
• Updated the minimum Node.js engine requirement to >=22.0.0
• Updated the development Docker image from Node 18 to Node 22
• Updated the documented Node.js recommendation to 22.x
• Updated the documented npm version to 10

Testing

• npx gulp passed
• Stylelint passed
• ESLint passed
• Translation tests passed
• GitHub Actions YAML syntax validated
• Verified the project builds successfully on Node.js 22.20.0

The production server itself is not changed by this PR; the repository configuration is updated to align with the planned server upgrade.

Fixes #4037