test: increase vm memory

This hopefully fixes the intermittent failures.

Signed-off-by: Ophestra <cat@gensokyo.uk>

test/configuration.nix

@@ -82,13 +82,18 @@
     jack.enable = true;
   };
 
-  virtualisation.qemu.options = [
+  virtualisation = {
+    # Hopefully reduces spurious test failures:
+    memorySize = 4096;
+
+    qemu.options = [
       # Need to switch to a different GPU driver than the default one (-vga std) so that Sway can launch:
       "-vga none -device virtio-gpu-pci"
 
       # Increase Go test compiler performance:
       "-smp 8"
     ];
+  };
 
   environment.hakurei = {
     enable = true;