Add dependabot monitoring for npm, pip, gomod, and nuget (#273)

* Initial plan

* Update dependabot.yaml to include node, python, go, and dotnet dependencies

Co-authored-by: friggeri <106686+friggeri@users.noreply.github.com>

---------

Co-authored-by: copilot-swe-agent[bot] <198982749+Copilot@users.noreply.github.com>
Co-authored-by: friggeri <106686+friggeri@users.noreply.github.com>

Author: Copilot

.github/dependabot.yaml

@@ -8,3 +8,31 @@ updates:
     directory: '/'
     schedule:
       interval: 'weekly'
+  # Node.js dependencies
+  - package-ecosystem: 'npm'
+    directory: '/nodejs'
+    schedule:
+      interval: 'weekly'
+  - package-ecosystem: 'npm'
+    directory: '/test/harness'
+    schedule:
+      interval: 'weekly'
+  - package-ecosystem: 'npm'
+    directory: '/cookbook/nodejs/recipe'
+    schedule:
+      interval: 'weekly'
+  # Python dependencies
+  - package-ecosystem: 'pip'
+    directory: '/python'
+    schedule:
+      interval: 'weekly'
+  # Go dependencies
+  - package-ecosystem: 'gomod'
+    directory: '/go'
+    schedule:
+      interval: 'weekly'
+  # .NET dependencies
+  - package-ecosystem: 'nuget'
+    directory: '/dotnet'
+    schedule:
+      interval: 'weekly'