ci: fix issue with gradle and snyk monitor step

[andrewb1269hg]

snyk monitor has a problem where it does not run due to gradle project aggregation. The --all-projects creates thousands of artifacts and --all-subprojects fail completely.

Here's the command we've been using to test locally:

snyk monitor --all-projects --policy-path=.snyk --trust-policies --org=hiero-consensus-node --debug

The --all-sub-projects flag on snyk monitor does not work at all, and it is aggregating results in snyk test.

The whole snyk workflow seems to be broken at this time.

The workflow has been disabled in the mainline through this PR here:
#17896

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