build: do not link against librt on linux

PR-URL: #29727
Fixes: #27377
Fixes: #29718
Reviewed-By: Michaël Zasso <targos@protonmail.com>
Reviewed-By: Colin Ihrig <cjihrig@gmail.com>
Reviewed-By: Richard Lau <riclau@uk.ibm.com>
Reviewed-By: Ruben Bridgewater <ruben@bridgewater.de>
Reviewed-By: Michael Dawson <michael_dawson@ca.ibm.com>
Reviewed-By: James M Snell <jasnell@gmail.com>

node.gypi

@@ -291,6 +291,11 @@
     [ 'OS=="sunos"', {
       'ldflags': [ '-Wl,-M,/usr/lib/ld/map.noexstk' ],
     }],
+    [ 'OS=="linux"', {
+      'libraries!': [
+        '-lrt'
+      ],
+    }],
     [ 'OS in "freebsd linux"', {
       'ldflags': [ '-Wl,-z,relro',
                    '-Wl,-z,now' ]