Drop nodejs test that started spontaneously failing.

It is unclear exactly what happened in the DNS response that has caused
this test to start breaking. However, since this is unrelated to any code
change, this can be attributed to a non-hermetic or broken test case.

See master failure:
https://buildkite.com/gvisor/pipeline/builds/10462#ae46ee7c-855c-4efe-8165-f0c694557cf9

This may be related to nodejs/node#28790, where
older versions of node are not parsing this field correctly? However, we
would like to retain other tests from the same older version of node.

For posterity, the current serial field appears as:

; <<>> DiG 9.17.19-1-Debian <<>> nodejs.org -t SOA +multiline
;; global options: +cmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 56131
;; flags: qr rd ra; QUERY: 1, ANSWER: 1, AUTHORITY: 0, ADDITIONAL: 1

;; OPT PSEUDOSECTION:
; EDNS: version: 0, flags:; udp: 4096
;; QUESTION SECTION:
;nodejs.org.            IN SOA

;; ANSWER SECTION:
nodejs.org.             3402 IN SOA meera.ns.cloudflare.com. dns.cloudflare.com. (
                                2264470260 ; serial
                                10000      ; refresh (2 hours 46 minutes 40 seconds)
                                2400       ; retry (40 minutes)
                                604800     ; expire (1 week)
                                3600       ; minimum (1 hour)
                                )

;; Query time: 59 msec
;; SERVER: 127.0.0.1#53(127.0.0.1) (UDP)
;; WHEN: Thu Dec 09 10:35:57 PST 2021
;; MSG SIZE  rcvd: 102

PiperOrigin-RevId: 415308624

test/runtimes/exclude/nodejs12.4.0.csv

@@ -6,6 +6,7 @@ doctool/test-make-doc.js,b/68848110,Expected to fail.
 internet/test-dgram-multicast-set-interface-lo.js,b/162798882,
 internet/test-doctool-versions.js,,Broken test
 internet/test-uv-threadpool-schedule.js,,Broken test
+internet/test-dns.js,,Broken test
 parallel/test-dgram-bind-fd.js,b/132447356,
 parallel/test-dgram-socket-buffer-size.js,b/68847921,
 parallel/test-dns-channel-timeout.js,b/161893056,