Add uv ecosystem to dependabot and drop weekly lockfile workflow (#2919)

Author: Kludex

.github/dependabot.yml

@@ -1,9 +1,21 @@
 version: 2
 updates:
+  - package-ecosystem: "uv"
+    directory: "/"
+    schedule:
+      interval: monthly
+    cooldown:
+      default-days: 14
+    groups:
+      python-packages:
+        patterns:
+          - "*"
   - package-ecosystem: "github-actions"
     directory: "/"
     schedule:
       interval: monthly
+    cooldown:
+      default-days: 14
     groups:
       github-actions:
         patterns: