fix(hlth-csp): take the csp-checker build that stops failing on a 304

csp-checker 3.0.0 narrowed the healthy set to 2xx by failing every status at or above 300, which swept in 304. The health service then died on the first revalidated vhost: in CI job 104991065851 it reported element.<onion> unreachable with Status 304, and sys-service-terminator retried the unit 25 times over 1792 seconds before the job failed.

3.0.1 takes 304 out of the failure branch. The checker's own e2e suite verifies it in both directions: with the fix the second visit to a revalidating fixture reports 304 and stays healthy, without it the fixture reproduces the CI line verbatim.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>

roles/sys-ctl-hlth-csp/meta/services.yml

@@ -8,4 +8,4 @@ csp:
       categories: [web]
 csp-checker:
   image: ghcr.io/kevinveenbirkenbach/csp-checker
-  version: 3.0.0
+  version: 3.0.1