build: remove PVS

We already have an extensive suite of static analysis tools we use,
which causes a fair bit of redundancy as we get duplicate warnings. PVS
is also prone to give false warnings which creates a lot of work to
identify and disable.

src/nvim/message.c

@@ -1,6 +1,3 @@
-// This is an open source non-commercial project. Dear PVS-Studio, please check
-// it. PVS-Studio Static Code Analyzer for C, C++ and C#: http://www.viva64.com
-
 // message.c: functions for displaying messages on the command line
 
 #include <assert.h>
@@ -2116,7 +2113,7 @@ static void msg_puts_display(const char *str, int maxlen, int attr, int recurse)
       msg_ext_last_attr = attr;
     }
     // Concat pieces with the same highlight
-    size_t len = strnlen(str, (size_t)maxlen);  // -V781
+    size_t len = strnlen(str, (size_t)maxlen);
     ga_concat_len(&msg_ext_last_chunk, str, len);
     msg_ext_cur_len += len;
     return;