Use os.execv instead of subprocess.run when no further action is taken.

This prevents the underlying file from being marked busy while a
long-running action is happening (e.g. eureka is open).

dcc/eureka.py

@@ -1,6 +1,6 @@
 import dcc.doom_base
 import dcc.config
-import subprocess
+import os
 
 
 class Eureka(dcc.doom_base.WadMap):
@@ -24,7 +24,7 @@ class Eureka(dcc.doom_base.WadMap):
         if complevel == "11" or complevel == "21":
             port = "mbf"
 
-        subprocess.run(
+        os.execvp("eureka",
             ["eureka"] + ["-iwad", iwad] + ["-w", parsed_args.map]
             + ["-p", port] + [mw]
         )