fix: update PHP version to 8.1 to match composer.json requirements (#732)

Co-authored-by: Devin AI <158243242+devin-ai-integration[bot]@users.noreply.github.com>
Co-authored-by: Max Prilutskiy <maks.prilutskiy@gmail.com>

Author: devin-ai-integration[bot]

.github/workflows/publish-php-sdk.yml

@@ -21,7 +21,7 @@ jobs:
       - name: Setup PHP
         uses: shivammathur/setup-php@v2
         with:
-          php-version: '8.0'
+          php-version: '8.1'
           extensions: mbstring, intl
           coverage: none
           tools: composer:v2
@@ -70,7 +70,7 @@ jobs:
       - name: Setup PHP
         uses: shivammathur/setup-php@v2
         with:
-          php-version: '8.0'
+          php-version: '8.1'
           extensions: mbstring, intl
           coverage: none
           tools: composer:v2