minor #6965 Update minimum PHP version (javiereguiluz)

This PR was merged into the 4.x branch.

Discussion
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Update minimum PHP version

## Summary
- update README to require PHP 8.1

## Testing
- `git status --short`

Commits
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93f2414 docs: update minimum PHP version to 8.1

Author: javiereguiluz

README.md

@@ -8,7 +8,7 @@ EasyAdmin is a fast, beautiful and modern admin generator for Symfony applicatio
 Installation
 ------------
 
-EasyAdmin 4 requires PHP 8.0.2 or higher and Symfony 5.4 or higher. Run the
+EasyAdmin 4 requires PHP 8.1 or higher and Symfony 5.4 or higher. Run the
 following command to install it in your application:
 
 ```bash
@@ -26,7 +26,7 @@ Versions
 
 | Repository Branch | EasyAdmin Version | Symfony Compatibility  | PHP Compatibility | Status               | Docs
 | ----------------- | ----------------- | ---------------------- | ----------------- | -------------------- | ---
-| `4.x`             | `4.x`             | `5.4`, `6.x` and `7.x` | `8.0.2` or higher | New features and bug fixes | [Read Docs](https://symfony.com/bundles/EasyAdminBundle/4.x/index.html)
+| `4.x`             | `4.x`             | `5.4`, `6.x` and `7.x` | `8.1` or higher | New features and bug fixes | [Read Docs](https://symfony.com/bundles/EasyAdminBundle/4.x/index.html)
 | `3.x`             | `3.x`             | `4.4`, and `5.x`       | `7.2.5` or higher | Bug fixes only; no new features | [Read Docs](https://symfony.com/bundles/EasyAdminBundle/3.x/index.html)
 | `2.x`             | `2.x`             | `4.x`, and `5.x`       | `7.1.3` or higher | No longer maintained | [Read Docs](https://symfony.com/bundles/EasyAdminBundle/2.x/index.html)
 | `1.x`             | `1.x`             | `2.x`, `3.x` and `4.x` | `5.3.0` or higher | No longer maintained | -