PMM-7 Update dependabot config (percona#95)

Author: artemgavrilov

.github/dependabot.yml

@@ -1,6 +1,19 @@
+---
 version: 2
 updates:
   - package-ecosystem: "gomod"
     directory: "/"
     schedule:
-      interval: "monthly"
+      interval: "weekly"
+  - package-ecosystem: "gomod"
+    directory: "/tools"
+    schedule:
+      interval: "weekly"
+  - package-ecosystem: "docker"
+    directory: "/"
+    schedule:
+      interval: "weekly"
+  - package-ecosystem: "github-actions"
+    directory: "/"
+    schedule:
+      interval: "weekly"