chore: remove bmad-cybersec entries from dependabot config

packages/bmad-cybersec/ is intentionally gitignored (.gitignore:7,
"Development framework — not part of DojoLM"). The two dependabot
entries pointing at /packages/bmad-cybersec/framework and
/packages/bmad-cybersec/validators have no package.json to scan and
produce noise. Remove both. If the framework is ever re-tracked,
re-add the entries (and restore the CI test steps removed from
ci.yml in b94c5a1).

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

Author: SchenLong

.github/dependabot.yml

@@ -59,27 +59,6 @@ updates:
       - "dependencies"
       - "web"
 
-  # bmad-cybersec packages
-  - package-ecosystem: "npm"
-    directory: "/packages/bmad-cybersec/framework"
-    schedule:
-      interval: "weekly"
-      day: "monday"
-    open-pull-requests-limit: 5
-    labels:
-      - "dependencies"
-      - "cybersec"
-
-  - package-ecosystem: "npm"
-    directory: "/packages/bmad-cybersec/validators"
-    schedule:
-      interval: "weekly"
-      day: "monday"
-    open-pull-requests-limit: 5
-    labels:
-      - "dependencies"
-      - "cybersec"
-
   # GitHub Actions
   - package-ecosystem: "github-actions"
     directory: "/"