Bump cockroachdb/cockroach from v25.2.4 to v25.3.0 in /tooling/docker

Bumps cockroachdb/cockroach from v25.2.4 to v25.3.0.

---
updated-dependencies:
- dependency-name: cockroachdb/cockroach
  dependency-version: v25.3.0
  dependency-type: direct:production
...

Signed-off-by: dependabot[bot] <[email protected]>

Author: dependabot[bot]

tooling/docker/cockroachdb.Dockerfile

@@ -1,3 +1,3 @@
 # CockroachDB
 # See https://hub.docker.com/r/cockroachdb/cockroach
-FROM docker.io/cockroachdb/cockroach:v25.2.4
+FROM docker.io/cockroachdb/cockroach:v25.3.0