Deprecated ReflectionParameter::getClass() Errors After Switching Back to Laravel 5.5 from Laravel 6

After switching from my Laravel 6 branch back to my Laravel 5.5 branch, I’m encountering several deprecation errors related to the ReflectionParameter::getClass() method in my application. The errors are as follows:

Deprecated: Method ReflectionParameter::getClass() is deprecated in /private/var/www/finconnect/vendor/laravel/framework/src/Illuminate/Container/Container.php on line 811
Deprecated: Method ReflectionParameter::getClass() is deprecated in /private/var/www/finconnect/vendor/laravel/framework/src/Illuminate/Container/Container.php on line 885

I have attempted multiple solutions to resolve these errors, including:

Clearing various Laravel caches (php artisan cache:clear, php artisan config:clear, php artisan view:clear)
Removing the vendor directory and reinstalling dependencies (rm -rf vendor/, composer clearcache, composer dump-autoload -o)
The documentation suggests that ReflectionParameter::getClass() is deprecated as of PHP 8, recommending the use of ReflectionParameter::getType() instead. However, I’m currently running PHP 7.3, as confirmed by php -v, and my Valet setup appears to be healthy.

PHP 7.3.33 (cli) (built: Dec 27 2023 06:53:55) ( NTS )

+——————————————+———-+
| Check | Success? |
+——————————————+———-+
| Is Valet fully installed? | Yes |
| Is Valet config valid? | Yes |
| Is Homebrew installed? | Yes |
| Is DnsMasq installed? | Yes |
| Is Dnsmasq running? | Yes |
| Is Dnsmasq running as root? | Yes |
| Is Nginx installed? | Yes |
| Is Nginx running? | Yes |
| Is Nginx running as root? | Yes |
| Is PHP installed? | Yes |
| Is linked PHP ([email protected]) running? | Yes |
| Is linked PHP ([email protected]) running as root? | Yes |
| Is valet.sock present? | Yes |
+——————————————+———-+

I’m puzzled by these deprecation notices since they’re supposed to only apply to PHP 8 and above. Has anyone faced similar issues when working with Laravel 5.5 on PHP 7.3, or does anyone have insights on how to resolve these deprecation warnings? Any help or suggestions would be greatly appreciated.