Add CODEOWNERS and dependabot.yml for security compliance

- Add CODEOWNERS file with team ownership (@cloudwebrtc @lukasIO @xianshijing-lk)
- Add dependabot.yml for automated security updates (pip, github-actions)
- Configure versioning-strategy to only update for security fixes

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

Author: xianshijing-lk

.github/CODEOWNERS

@@ -0,0 +1,4 @@
+# CODEOWNERS for python-sdks
+# These owners will be requested for review on all PRs
+
+* @cloudwebrtc @lukasIO @xianshijing-lk

.github/dependabot.yml

@@ -0,0 +1,14 @@
+version: 2
+updates:
+  - package-ecosystem: "pip"
+    directory: "/"
+    schedule:
+      interval: "weekly"
+    open-pull-requests-limit: 10
+    versioning-strategy: "increase-if-necessary"
+
+  - package-ecosystem: "github-actions"
+    directory: "/"
+    schedule:
+      interval: "weekly"
+    open-pull-requests-limit: 5