Known issues with graphics cards: drop mention of Tails 3.2.

It's been released a long time ago so is probably not very useful
at this point anymore. Besides, some more improvements are coming
in 3.9.

wiki/src/support/known_issues/graphics.mdwn

@@ -247,8 +247,7 @@ Ticket: #15116
 
 ### Workaround
 
-This problem has been fixed in Tails 3.2 for some of these graphic
-cards.
+This problem has been fixed for some of these graphic cards.
 
 Otherwise, try adding `nouveau.noaccel=1` or `nouveau.modeset=0` to the
 [[startup options|doc/first_steps/startup_options#boot_loader_menu]].
@@ -277,8 +276,7 @@ Ticket: #15116
 
 ### Workaround
 
-This problem has been fixed in Tails 3.2 for some of these graphic
-cards.
+This problem has been fixed for some of these graphic cards.
 
 Otherwise, try adding `nouveau.noaccel=1` or `nouveau.modeset=0` to the
 [[startup options|doc/first_steps/startup_options#boot_loader_menu]].