Remove mod_http2/mod_md from Apache images, add build gate (CVE-2026-119618)

mod_http2 (httpd 2.4.55-2.4.70) assign_headers() heap corruption -> RCE;
AlmaLinux has no fixed httpd yet. Nothing in WHP uses HTTP/2 inside a
container (HAProxy edge terminates h2/h3 and speaks HTTP/1.1 to backends),
so uninstall mod_http2 (and mod_md if ever present) from cac, cac-fpm and
shared-httpd. scripts/httpd-h2-md-gate.sh fails the build if http2_module,
proxy_http2_module or md_module is loadable or `httpd -t` fails, writes
/etc/whp-httpd-version and the images get LABEL org.whp.httpd-h2-md=removed.

Co-Authored-By: Claude Sonnet 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_0185ukXjXyosSkunDsdWz3mb

.gitea/workflows/build-push.yaml

@@ -56,6 +56,7 @@ jobs:
             scripts/lsphp-src-overlay.sh \
             scripts/lsphp-abi-gate.sh \
             scripts/tune-mpm.sh \
+            scripts/httpd-h2-md-gate.sh \
             scripts/tests/lsphp-info-probe.test.sh \
             scripts/lsphp-repo-version.sh \
             scripts/tests/lsphp-repo-version.test.sh \