Adds a popup for logging in with an unrecommended byond version (#93742)

## About The Pull Request

Adds `GLOB.unrecommended_builds`, for byond build which are broken for
the end user in some way, but not in a way that warrants outright
blacklisting players from connecting with them

Looks like this (Ignore the number I changed it for testing purposes) 

<img width="493" height="267" alt="image"
src="https://github.com/user-attachments/assets/d31636e8-a106-4d13-a8fa-aee6a50c6d27"
/>

Uses this system for the new byond build, 1670+, which breaks text
rendering

Also adds 1670+ to the list of builds to warn on compile

## Why It's Good For The Game

1670 broke the compilation step, probably permanently

Whether we will fix this or flip a pragma or w/e remains to be seen, but
until then we can tell people to compile an earlier version

1670 also broke the user experience, causing map text to show up as
really big. This will be fixed in an upcoming version
<https://www.byond.com/forum/post/2983385>

## Changelog

🆑 Melbert
qol: If you are on Byond 516.1670+, you will get an alert on login that
your build is less than functional
/🆑

code/modules/client/client_procs.dm

@@ -4,8 +4,11 @@
 
 GLOBAL_LIST_INIT(blacklisted_builds, list(
 	"1622" = "Bug breaking rendering can lead to wallhacks.",
-	))
-
+))
+GLOBAL_LIST_INIT(unrecommended_builds, list(
+	"1670" = "Bug breaking in-world text rendering.",
+	"1671" = "Bug breaking in-world text rendering.",
+))
 #define LIMITER_SIZE 5
 #define CURRENT_SECOND 1
 #define SECOND_COUNT 2