mdt-37145: Upgrade to PHP 8.3 (#18)

Author: naveenvalecha

assets/github-actions/workflows/pantheon_deploy.yml

@@ -41,7 +41,7 @@ jobs:
       - name: Setup PHP and tools
         uses: shivammathur/setup-php@v2
         with:
-          php-version: '8.2'
+          php-version: '8.3'
           tools: composer:v2
           extensions: mbstring, gd, intl, yaml, bcmath, curl
       - name: Execute build script

assets/pantheon/pantheon.upstream.yml

@@ -3,7 +3,7 @@
 # Override the defaults specified here in a site-specific `pantheon.yml` file.
 # For more information see: https://pantheon.io/docs/pantheon-upstream-yml
 api_version: 1
-php_version: 8.2
+php_version: 8.3
 database:
   version: 10.6
 drush_version: 10