More accurate reviewers and assigness

Author: vjovanov

.github/CODEOWNERS

@@ -1,4 +1,8 @@
-*       @oracle/graalvm-reachability-maintainer
-tests/tck-build-logic/src/main/resources/allowed-docker-images/* @matneu @matteoldani
+metadata/*       @oracle/graalvm-reachability-maintainer
+tests/*          @oracle/graalvm-reachability-maintainer
+tests/tck-build-logic/src/main/resources/allowed-docker-images/* @matneu
 library-and-framework-list.json @fniephaus
 .github/* @vjovanov
+docs/*    @vjovanov
+gradle/*  @vjovanov
+/*        @vjovanov

.github/dependabot.yml

@@ -8,5 +8,7 @@ updates:
     directory: "/tests/tck-build-logic/src/main/resources/allowed-docker-images"
     reviewers:
       - "matneu"
+    assignees:
+      - "jormundur00"
     schedule:
       interval: "daily"