randomenv: remove /proc/ access

The data we try and gather in this file is on a best-effort basis,
however in this instance, for certain users, it's just producing spam.
This could (possibly?) be solved with further snap/apparmor
configuration, however given that no-one is actively working on
packaging, we could instead drop this (one of many), sources of
dynamic environment data.

Closes bitcoin-core/packaging#115.

src/randomenv.cpp

@@ -222,18 +222,6 @@ void RandAddDynamicEnv(CSHA512& hasher)
     if (getrusage(RUSAGE_SELF, &usage) == 0) hasher << usage;
 #endif
 
-#ifdef __linux__
-    AddFile(hasher, "/proc/diskstats");
-    AddFile(hasher, "/proc/vmstat");
-    AddFile(hasher, "/proc/schedstat");
-    AddFile(hasher, "/proc/zoneinfo");
-    AddFile(hasher, "/proc/meminfo");
-    AddFile(hasher, "/proc/softirqs");
-    AddFile(hasher, "/proc/stat");
-    AddFile(hasher, "/proc/self/schedstat");
-    AddFile(hasher, "/proc/self/status");
-#endif
-
 #ifdef HAVE_SYSCTL
 #  ifdef CTL_KERN
 #    if defined(KERN_PROC) && defined(KERN_PROC_ALL)