Prepare release v0.18.0 (#462)

<!-- This is an auto-generated comment: release notes by coderabbit.ai
-->

## Summary by CodeRabbit

## Release Notes

- **New Features**
	- Expanded build process to include the `cozystack-api` component.
- Updated image versions for `cozystack`, `darkhttpd`, and other
components to improve performance and stability.

- **Bug Fixes**
- Updated image digests for various components, ensuring the latest
updates and security patches are applied.

- **Documentation**
- Incremented version numbers across multiple configuration files for
clarity and consistency.

- **Chores**
- Updated various package versions in the version map for better
dependency management.

<!-- end of auto-generated comment: release notes by coderabbit.ai -->

Signed-off-by: Andrei Kvapil <kvapss@gmail.com>

Makefile

@@ -6,6 +6,7 @@ build:
 	make -C packages/apps/mysql image
 	make -C packages/apps/clickhouse image
 	make -C packages/apps/kubernetes image
+	make -C packages/system/cozystack-api image
 	make -C packages/system/cilium image
 	make -C packages/system/kubeovn image
 	make -C packages/system/dashboard image
@@ -35,4 +36,4 @@ assets:
 test:
 	make -C packages/core/testing apply
 	make -C packages/core/testing test
-	make -C packages/core/testing delete
+	make -C packages/core/testing test-applications