chore: update JetBrains IDE icons (coder#16065)

JetBrains have updated the icons as per
https://www.jetbrains.com/company/brand/#logos-and-icons.
Noticed while adding coder#16057

Author: matifali

site/src/theme/icons.json

@@ -54,6 +54,7 @@
 	"java.svg",
 	"javascript.svg",
 	"jax.svg",
+	"jetbrains-toolbox.svg",
 	"jfrog.svg",
 	"jupyter.svg",
 	"k8s.png",