Fix readme images

Author: SerafimArts

README.md

@@ -1,7 +1,5 @@
 <a href="https://github.com/php-type-language" target="_blank">
-    <picture>
-        <img align="center" src="https://github.com/php-type-language/.github/blob/master/assets/dark.png?raw=true">
-    </picture>
+    <img align="center" src="https://github.com/php-type-language/.github/blob/master/assets/dark.png?raw=true">
 </a>
 
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