mpick: relax pledge for redirects

This allows mpick to create files and run popen.
In the future, we can only pledge this if these features are actually used.

mpick.c

@@ -1464,7 +1464,7 @@ main(int argc, char *argv[])
 			exit(1);
 		}
 
-	xpledge("stdio rpath", "");
+	xpledge("stdio rpath wpath cpath proc exec", 0);
 
 	void *cb = need_thr ? collect : oneline;
 	if (argc == optind && isatty(0))