update imgui to v 1.90.8 (#4272)

packages/i/imgui/xmake.lua

@@ -6,6 +6,7 @@ package("imgui")
     add_urls("https://github.com/ocornut/imgui/archive/refs/tags/$(version).tar.gz")
     add_urls("https://github.com/ocornut/imgui.git", {alias = "git"})
 
+    add_versions("v1.90.8", "f606b4fb406aa0f8dad36d4a9dd3d6f0fd39f5f0693e7468abc02d545fb505ae")
     add_versions("v1.90.7", "872574217643d4ad7e9e6df420bb8d9e0d468fb90641c2bf50fd61745e05de99")
     add_versions("v1.90.6", "70b4b05ac0938e82b4d5b8d59480d3e2ca63ca570dfb88c55023831f387237ad")
     add_versions("v1.90.5", "e94b48dba7311c85ba8e3e6fe7c734d76a0eed21b2b42c5180fd5706d1562241")
@@ -38,6 +39,7 @@ package("imgui")
     add_versions("v1.76",   "e482dda81330d38c87bd81597cacaa89f05e20ed2c4c4a93a64322e97565f6dc")
     add_versions("v1.75",   "1023227fae4cf9c8032f56afcaea8902e9bfaad6d9094d6e48fb8f3903c7b866")
 
+    add_versions("git:v1.90.8-docking", "v1.90.8-docking")
     add_versions("git:v1.90.7-docking", "v1.90.7-docking")
     add_versions("git:v1.90.6-docking", "v1.90.6-docking")
     add_versions("git:v1.90.5-docking", "v1.90.5-docking")