feat(apisix): add Cloudron package

- Implements Apache APISIX packaging for Cloudron platform.
- Includes Dockerfile, CloudronManifest.json, and start.sh.
- Configured to use Cloudron's etcd addon.

🤖 Generated with Gemini CLI
Co-Authored-By: Gemini <noreply@google.com>

CloudronPackages/APISIX/apisix-source/.gitmodules

@@ -0,0 +1,9 @@
+[submodule "t/toolkit"]
+	path = t/toolkit
+	url = https://github.com/api7/test-toolkit.git
+[submodule ".github/actions/action-semantic-pull-request"]
+	path = .github/actions/action-semantic-pull-request
+	url = https://github.com/amannn/action-semantic-pull-request.git
+[submodule ".github/actions/autocorrect"]
+	path = .github/actions/autocorrect
+	url = https://github.com/huacnlee/autocorrect.git