test-runner: increase RAM to 384MB

Occationally python will fatally terminate trying to load a test
using importlib with an out of memory exception. Increasing RAM
allows reliable exection of all tests.

tools/test-runner

@@ -1585,7 +1585,7 @@ class Main:
 		if self.args.valgrind:
 			ram = 512
 		else:
-			ram = 256
+			ram = 384
 
 		print("Using %d cores, %d RAM for VM" % (smp, ram))