Fix regex code block release notes

release notes/v0.54.0.md

@@ -189,7 +189,7 @@ Note: that prior k6 version v0.54, Golang's type `math/big.Int` mapped to anothe
 
 Regexp dotall support - letting you match newline characters with `.`.
 
-``javascript
+```javascript
 const str1 = "bar\nexample foo example";
 
 const regex1 = /bar.example/s;