Docs: Ignore link-checking for Apache mailing list and GNU website

[manuzhang]

The link check has been failing frequently.

[✖] http://mail-archives.apache.org/mod_mbox/flink-dev/202008.mbox/%3cCABi+2jQCo3MsOa4+ywaxV5J-Z8TGKNZDX-pQLYB-dG+dVUMiMw@mail.gmail.com%3e → Status: 0 Error: ESOCKETTIMEDOUT
    at ClientRequest.<anonymous> (/usr/local/lib/node_modules/markdown-link-check/node_modules/request/request.js:816:19)
    at Object.onceWrapper (node:events:633:28)
    at ClientRequest.emit (node:events:519:28)
    at TLSSocket.emitRequestTimeout (node:_http_client:845:9)
    at Object.onceWrapper (node:events:633:28)
    at TLSSocket.emit (node:events:531:35)
    at Socket._onTimeout (node:net:590:8)
    at listOnTimeout (node:internal/timers:573:17)
    at process.processTimers (node:internal/timers:514:7) {
  code: 'ESOCKETTIMEDOUT',
  connect: false

[✖] https://www.gnu.org/software/make/manual/make.html → Status: 0 Error: connect ECONNREFUSED 209.51.188.116:443
    at TCPConnectWrap.afterConnect [as oncomplete] (node:net:1606:16) {
  errno: -111,
  code: 'ECONNREFUSED',
  syscall: 'connect',
  address: '209.51.188.116',
  port: 443
}

[manuzhang]

cc @stevenzwu @pvary to check if I've missed any recent progress on hidden partitioning support in Flink.

[pvary]

I'm not sure about the state of the hidden partitioning, but the link checker is very-very flaky. We should fix that first and then decide independently about changes in the doc

[manuzhang]

@pvary do you see other link check failure than this one?

[manuzhang]

Another option is to exclude this link from check.

[Fokko]

but the link checker is very-very flaky

Yes, I agree, it is creating more frustration than actually helping right now :( I'm okay with disabling it until we find something better

[manuzhang]

Superseded by #10404