Exclude eng/common from Dependabot scanning (#6925)

* Initial plan

* Exclude eng/common from dependabot scanning

Co-authored-by: danieljurek <[email protected]>

* Add npm ecosystem with exclude-paths for eng/common, keep vcpkg without exclusions

Co-authored-by: danieljurek <[email protected]>

---------

Co-authored-by: copilot-swe-agent[bot] <[email protected]>
Co-authored-by: danieljurek <[email protected]>

Author: Copilot

.github/dependabot.yml

@@ -5,3 +5,9 @@ updates:
     directory: "/"
     schedule:
       interval: weekly
+  - package-ecosystem: "npm"
+    directory: "/"
+    schedule:
+      interval: weekly
+    exclude-paths:
+      - "eng/common/**"