Studio: Remove deprecated PHP versions 7.2 and 7.3

[epeicher]

Related issues

• Fixes STU-1114
• Remove support for PHP 7.2 and 7.3 WordPress/wordpress-playground#3127

Proposed Changes

• Removed PHP 7.2 and 7.3 from SupportedPHPVersions array in common/types/php-versions.ts
• Updated CLI commands to use common/types/php-versions instead of @php-wasm/universal for PHP version types
• Modified cli/commands/site/create.ts to import from common types
• Modified cli/commands/site/set.ts to import from common types
• Modified cli/lib/utils.ts to import from common types

These PHP versions are no longer supported by WordPress Playground and cause timeout errors when attempting to create sites.

Testing Instructions

• Build the app: npm run cli:build && npm start
• Test that creating a new site works with PHP 7.4 and above (8.0, 8.1, 8.2, 8.3, 8.4)
• Verify PHP 7.2 and 7.3 are no longer available in the UI dropdown for site creation
• Test CLI: npm run cli:build && node dist/cli/main.js site create --name test-site --php 8.3
• Verify CLI site create command does not accept --php 7.2 or --php 7.3 options
• Test changing PHP version on existing site works with supported versions

Pre-merge Checklist

• Have you checked for TypeScript, React or other console errors?