Do not fail a release when markdown-link-check check fails as it is flaky

[pingtimeout]

We are being rate limited by medium and that fails the check markdown-link-check. Problem: the release workflows currently require all checks to pass. This commit skips the verification for the markdown-link-check.

[dimas-b]

Related PR: #3102

[snazy]

This is probably more flexible.
We already have the name of the required checks in .asf.yaml, and can get the names as a JSON array via yq (available on GH runners).

Suggested change

	local num_invalid_checks_retrieval_command="gh api repos/${repo_info}/commits/${commit_sha}/check-runs --jq '[.check_runs[] | select(.conclusion != \"success\" and .conclusion != \"skipped\" and (.name | startswith(\"Release - \") | not) and (.name != \"markdown-link-check\"))] | length'"
	local required_check_names_array="$(yq -o json '.github.protected_branches.main.required_status_checks.contexts' < .asf.yaml)"
	#
	local num_invalid_checks_retrieval_command="$(gh api repos/${repo_info}/commits/${commit_sha}/check-runs --jq "
	[
	.check_runs[] |
	select(
	.conclusion != \"success\" and
	.conclusion != \"skipped\" and
	(
	.name as \$name |
	any(
	${required_check_names_array}[] == \$name
	)
	)
	)
	]
	| length
	")"

The yq command yields:

[
  "Unit Tests",
  "Quarkus Tests",
  "Quarkus Integration Tests",
  "Quarkus Admin Tests",
  "Integration Tests",
  "regtest",
  "spark-plugin-regtest",
  "site",
  "Helm tests"
]

[pingtimeout]

I want to run a full release cycle before merging this, and that requires all CI checks to pass (>20 minutes) plus another 20 minutes to fully package Polaris and its components. Let's open a separate PR for that so that I can merge this PR and release 1.3.0 in about 45 minutes.