deps: do not link against librt

It is not needed, and causes an unnecessary runtime dependency with some
linkers, such as devtoolset-6 on centos7-ppc64le.

See: #29718

PR-URL: #29729
Reviewed-By: Ruben Bridgewater <ruben@bridgewater.de>
Reviewed-By: Beth Griggs <Bethany.Griggs@uk.ibm.com>
Reviewed-By: David Carlier <devnexen@gmail.com>

Author: sam-github

deps/uv/uv.gyp

@@ -244,7 +244,7 @@
             'src/unix/sysinfo-memory.c',
           ],
           'link_settings': {
-            'libraries': [ '-ldl', '-lrt' ],
+            'libraries': [ '-ldl' ],
           },
         }],
         [ 'OS=="android"', {

deps/v8/gypfiles/v8.gyp

@@ -1975,8 +1975,7 @@
                   # library order and break (see crbug.com/469973).
                   # These libraries do not exist on Mac hosted builds.
                   'libraries': [
-                    '-ldl',
-                    '-lrt'
+                    '-ldl'
                   ]
                 }]
               ]