test: Add directories to dependabot.yaml

Adds the following directories to dependabot.yaml:
- /tests/host_tools/uffd/
- /tests/integration_tests/security/demo_seccomp/

Cargo.lock files under these directories were not updated by depedabot.
See PR #3850.

Signed-off-by: Takahiro Itazuri <[email protected]>

Author: zulinx86

.github/dependabot.yml

@@ -1,10 +1,26 @@
 version: 2
 updates:
-  - package-ecosystem: "cargo" 
+  - package-ecosystem: "cargo"
     directory: "/"
     schedule:
       interval: "weekly"
       day: "monday"
     allow:
       - dependency-type: "all"
     open-pull-requests-limit: 100
+  - package-ecosystem: "cargo"
+    directory: "/tests/host_tools/uffd/"
+    schedule:
+      interval: "weekly"
+      day: "monday"
+    allow:
+      - dependency-type: "all"
+    open-pull-requests-limit: 100
+  - package-ecosystem: "cargo"
+    directory: "/tests/integration_tests/security/demo_seccomp/"
+    schedule:
+      interval: "weekly"
+      day: "monday"
+    allow:
+      - dependency-type: "all"
+    open-pull-requests-limit: 100