Disable BWC testing for ILM _meta backport (elastic#73625)

This commit disables BWC tests until the PRs adding `_meta` to ILM policies can be backported and
version constants added.

Relates: elastic#73515, elastic#73624

build.gradle

@@ -170,9 +170,9 @@ tasks.register("verifyVersions") {
  * after the backport of the backcompat code is complete.
  */
 
-boolean bwc_tests_enabled = true
+boolean bwc_tests_enabled = false
 // place a PR link here when committing bwc changes:
-String bwc_tests_disabled_issue = ""
+String bwc_tests_disabled_issue = "https://github.com/elastic/elasticsearch/pull/73624"
 /*
  * FIPS 140-2 behavior was fixed in 7.11.0. Before that there is no way to run elasticsearch in a
  * JVM that is properly configured to be in fips mode with BCFIPS. For now we need to disable