Add: Include dependency updates in release changelog

Update dependabot config to create commits starting with `Deps:` to
include the dependency update changes in the release changelog.

.github/dependabot.yml

@@ -1,16 +1,20 @@
 version: 2
 updates:
-- package-ecosystem: pip
-  directory: "/"
-  schedule:
-    interval: weekly
-    time: "04:00"
-  open-pull-requests-limit: 10
-  allow:
-  - dependency-type: direct
-  - dependency-type: indirect
+  - package-ecosystem: pip
+    directory: "/"
+    schedule:
+      interval: weekly
+      time: "04:00"
+    open-pull-requests-limit: 10
+    allow:
+      - dependency-type: direct
+      - dependency-type: indirect
+    commit-message:
+      prefix: "Deps"
 
-- package-ecosystem: "github-actions"
-  directory: "/"
-  schedule:
-    interval: "weekly"
+  - package-ecosystem: "github-actions"
+    directory: "/"
+    schedule:
+      interval: "weekly"
+    commit-message:
+      prefix: "Deps"