ci: add pip package ecosystem support to dependabot configuration

Author: liuruibin

.github/dependabot.yml

@@ -7,10 +7,18 @@ updates:
       timezone: "Asia/Shanghai"
       day: "friday"
     target-branch: "v2"
+    groups:
+      python-dependencies:
+        patterns:
+          - "*"
   - package-ecosystem: "pip"
     directory: "/"
     schedule:
       interval: "weekly"
       timezone: "Asia/Shanghai"
       day: "friday"
     target-branch: "main"
+    groups:
+      python-dependencies:
+        patterns:
+          - "*"