PostgreSQL Anonymizer: Unbounded image-decode memory allocation (DoS) in anon.image_blur()

PostgreSQL Anonymizer's `anon.image_blur()` function doesn't check the declared dimension of the provided image, allowing an attacker to provide a small image with enormous declared dimensions. This vulnerability can be exploited to exhaust the memory of a backend and OOM-kill it (when ovecommit is on), which results in a cluster-wide crash recovery. The problem is resolved in PostgreSQL Anonymizer 3.3.0 and later versions.