fix: php sdk publishing workflow

[devin-ai-integration]

PHP SDK Publishing Workflow Fix

Problem

The current PHP SDK publishing workflow was failing at the "Install dependencies for SDK" step because the version field validation was happening before the workflow had a chance to set a valid version.

Solution

1. Moved the version check and setting logic to occur before the composer install step
2. Set a default version in the PHP SDK's composer.json
3. Added better error handling for version bumping
4. Added debug logging for Packagist publishing

This fix ensures that on every push to main affecting the PHP SDK, a new version will be automatically published to Packagist with an incremented patch version.

Link to Devin run: https://app.devin.ai/sessions/6407d462e80c47b4b98a7af1e3565247
User: Max Prilutskiy (max@lingo.dev)

[devin-ai-integration]

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